dpu: llvm: lldb: DpuContext: fix initialization ordering

A DpuContext, wrapper of backends's `struct dpu_context_t` is constructed for
every LLDB Dpu instance. These instances cover a full rank.

Currently, a DpuContext instance is partialialy initialize at the first StopThreads
call  (i.e. when LLDB stop threads for investigation) on which Dpu is
currently allocated.

When LLDB resume threads with ResumeThreads call, it tries to resume threads from
all LLDB::Dpu instance. Though, this does not correspond to the number of requested Dpus.
Hence, LLDB manipulates unitialized object.

This commit fixes those report from `valgrind`:
```
==17528== Conditional jump or move depends on uninitialised value(s)
==17528==    at 0x182A1E: lldb_private::dpu::DpuContext::ContextReadyForResumeOrStep() (DpuContext.cpp:153)
==17528==    by 0x180C68: lldb_private::dpu::Dpu::ResumeThreads(llvm::SmallVector<unsigned int, 8u>*, bool) (Dpu.cpp:295)
==17528==    by 0x18069C: lldb_private::dpu::DpuRank::ResumeDpus() (DpuRank.cpp:125)
==17528==    by 0x17DDEB: lldb_private::process_dpu::ProcessDpu::Detach() (ProcessDpu.cpp:460)
==17528==    by 0x17D339: lldb_private::process_dpu::ProcessDpu::Kill() (ProcessDpu.cpp:512)
==17528==    by 0x1A8E70: lldb_private::process_gdb_remote::GDBRemoteCommunicationServerLLGS::Handle_k(StringExtractorGDBRemote&) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x1A904D: std::_Function_handler<lldb_private::process_gdb_remote::GDBRemoteCommunication::PacketResult (StringExtractorGDBRemote&, lldb_private::Status&, bool&, bool&), lldb_private::process_gdb_remote::GDBRemoteCommunicationServerLLGS::RegisterPacketHandlers()::{lambda(StringExtractorGDBRemote, lldb_private::Status&, bool&, bool&)#1}>::_M_invoke(std::_Any_data const&, StringExtractorGDBRemote&, lldb_priv
ate::Status&, bool&, bool&) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x19839D: lldb_private::process_gdb_remote::GDBRemoteCommunicationServer::GetPacketAndSendResponse(lldb_private::Timeout<std::ratio<1l, 1000000l> >, lldb_private::Status&, bool&, bool&) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x1A8A74: lldb_private::process_gdb_remote::GDBRemoteCommunicationServerLLGS::DataAvailableCallback() (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x1597DE: lldb_private::MainLoop::ProcessReadObject(int) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x1598A3: lldb_private::MainLoop::RunImpl::ProcessEvents() (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x159CCF: lldb_private::MainLoop::Run() (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==
==17528== Conditional jump or move depends on uninitialised value(s)
==17528==    at 0x180C6F: lldb_private::dpu::Dpu::ResumeThreads(llvm::SmallVector<unsigned int, 8u>*, bool) (Dpu.cpp:295)
==17528==    by 0x18069C: lldb_private::dpu::DpuRank::ResumeDpus() (DpuRank.cpp:125)
==17528==    by 0x17DDEB: lldb_private::process_dpu::ProcessDpu::Detach() (ProcessDpu.cpp:460)
==17528==    by 0x17D339: lldb_private::process_dpu::ProcessDpu::Kill() (ProcessDpu.cpp:512)
==17528==    by 0x1A8E70: lldb_private::process_gdb_remote::GDBRemoteCommunicationServerLLGS::Handle_k(StringExtractorGDBRemote&) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x1A904D: std::_Function_handler<lldb_private::process_gdb_remote::GDBRemoteCommunication::PacketResult (StringExtractorGDBRemote&, lldb_private::Status&, bool&, bool&), lldb_private::process_gdb_remote::GDBRemoteCommunicationServerLLGS::RegisterPacketHandlers()::{lambda(StringExtractorGDBRemote, lldb_private::Status&, bool&, bool&)#1}>::_M_invoke(std::_Any_data const&, StringExtractorGDBRemote&, lldb_priv
ate::Status&, bool&, bool&) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x19839D: lldb_private::process_gdb_remote::GDBRemoteCommunicationServer::GetPacketAndSendResponse(lldb_private::Timeout<std::ratio<1l, 1000000l> >, lldb_private::Status&, bool&, bool&) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x1A8A74: lldb_private::process_gdb_remote::GDBRemoteCommunicationServerLLGS::DataAvailableCallback() (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x1597DE: lldb_private::MainLoop::ProcessReadObject(int) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x1598A3: lldb_private::MainLoop::RunImpl::ProcessEvents() (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x159CCF: lldb_private::MainLoop::Run() (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x14C220: main_gdbserver(int, char**) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==
==17528== Conditional jump or move depends on uninitialised value(s)
==17528==    at 0x489E135: ci_debug_teardown_dpu (ufi_debug.c:443)
==17528==    by 0x488B339: dpu_finalize_fault_process_for_dpu (dpu_debug.c:120)
==17528==    by 0x182C1C: lldb_private::dpu::DpuContext::ResumeThreads(llvm::SmallVector<unsigned int, 8u>*) (DpuContext.cpp:120)
==17528==    by 0x180C9B: lldb_private::dpu::Dpu::ResumeThreads(llvm::SmallVector<unsigned int, 8u>*, bool) (Dpu.cpp:308)
==17528==    by 0x18069C: lldb_private::dpu::DpuRank::ResumeDpus() (DpuRank.cpp:125)
==17528==    by 0x17DDEB: lldb_private::process_dpu::ProcessDpu::Detach() (ProcessDpu.cpp:460)
==17528==    by 0x17D339: lldb_private::process_dpu::ProcessDpu::Kill() (ProcessDpu.cpp:512)
==17528==    by 0x1A8E70: lldb_private::process_gdb_remote::GDBRemoteCommunicationServerLLGS::Handle_k(StringExtractorGDBRemote&) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x1A904D: std::_Function_handler<lldb_private::process_gdb_remote::GDBRemoteCommunication::PacketResult (StringExtractorGDBRemote&, lldb_private::Status&, bool&, bool&), lldb_private::process_gdb_remote::GDBRemoteCommunicationServerLLGS::RegisterPacketHandlers()::{lambda(StringExtractorGDBRemote, lldb_private::Status&, bool&, bool&)#1}>::_M_invoke(std::_Any_data const&, StringExtractorGDBRemote&, lldb_priv
ate::Status&, bool&, bool&) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x19839D: lldb_private::process_gdb_remote::GDBRemoteCommunicationServer::GetPacketAndSendResponse(lldb_private::Timeout<std::ratio<1l, 1000000l> >, lldb_private::Status&, bool&, bool&) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x1A8A74: lldb_private::process_gdb_remote::GDBRemoteCommunicationServerLLGS::DataAvailableCallback() (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x1597DE: lldb_private::MainLoop::ProcessReadObject(int) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==
==17528== Conditional jump or move depends on uninitialised value(s)
==17528==    at 0x489E140: ci_debug_teardown_dpu (ufi_debug.c:443)
==17528==    by 0x488B339: dpu_finalize_fault_process_for_dpu (dpu_debug.c:120)
==17528==    by 0x182C1C: lldb_private::dpu::DpuContext::ResumeThreads(llvm::SmallVector<unsigned int, 8u>*) (DpuContext.cpp:120)
==17528==    by 0x180C9B: lldb_private::dpu::Dpu::ResumeThreads(llvm::SmallVector<unsigned int, 8u>*, bool) (Dpu.cpp:308)
==17528==    by 0x18069C: lldb_private::dpu::DpuRank::ResumeDpus() (DpuRank.cpp:125)
==17528==    by 0x17DDEB: lldb_private::process_dpu::ProcessDpu::Detach() (ProcessDpu.cpp:460)
==17528==    by 0x17D339: lldb_private::process_dpu::ProcessDpu::Kill() (ProcessDpu.cpp:512)
==17528==    by 0x1A8E70: lldb_private::process_gdb_remote::GDBRemoteCommunicationServerLLGS::Handle_k(StringExtractorGDBRemote&) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x1A904D: std::_Function_handler<lldb_private::process_gdb_remote::GDBRemoteCommunication::PacketResult (StringExtractorGDBRemote&, lldb_private::Status&, bool&, bool&), lldb_private::process_gdb_remote::GDBRemoteCommunicationServerLLGS::RegisterPacketHandlers()::{lambda(StringExtractorGDBRemote, lldb_private::Status&, bool&, bool&)#1}>::_M_invoke(std::_Any_data const&, StringExtractorGDBRemote&, lldb_priv
ate::Status&, bool&, bool&) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x19839D: lldb_private::process_gdb_remote::GDBRemoteCommunicationServer::GetPacketAndSendResponse(lldb_private::Timeout<std::ratio<1l, 1000000l> >, lldb_private::Status&, bool&, bool&) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x1A8A74: lldb_private::process_gdb_remote::GDBRemoteCommunicationServerLLGS::DataAvailableCallback() (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==    by 0x1597DE: lldb_private::MainLoop::ProcessReadObject(int) (in /scratch/wwolff/dpu_tools_rework_testsuite/bin/lldb-server-dpu)
==17528==
```

Author: wwolff42

lldb/source/Plugins/Process/Dpu/DpuContext.cpp

@@ -50,6 +50,10 @@ DpuContext::DpuContext(dpu_t *dpu, struct dpu_context_t *context,
   }
   running_threads[0] = 0;
   last_resume_threads[0] = 0;
+
+  m_context->bkp_fault = false;
+  m_context->dma_fault = false;
+  m_context->mem_fault = false;
 }
 
 DpuContext::~DpuContext() {
@@ -82,10 +86,6 @@ void DpuContext::UpdateRunningThreads() {
 bool DpuContext::StopThreads(uint32_t error_store_addr) {
   ResetScheduling();
 
-  m_context->bkp_fault = false;
-  m_context->dma_fault = false;
-  m_context->mem_fault = false;
-
   int ret = DPU_OK;
   ret =
       dpu_initialize_fault_process_for_dpu(m_dpu, m_context, error_store_addr);