[ARM] Enable cfi-icall for thumb triples (#102126)

Support for this was added back in 2016
(https://reviews.llvm.org/D27499), but never enabled in the driver.
Since then, it's been possible to enable this with an arm triple and the
-mthumb option, but not with a thumb triple.

This also caused -fsanitise=cfi to enable cfi-icall for arm triple but
not thumb triples, which caused spurious sanitiser failures if mixing
the two ISAs in one program.

Author: ostannard

clang/lib/Driver/ToolChain.cpp

@@ -1381,7 +1381,8 @@ SanitizerMask ToolChain::getSupportedSanitizers() const {
       SanitizerKind::Nullability | SanitizerKind::LocalBounds;
   if (getTriple().getArch() == llvm::Triple::x86 ||
       getTriple().getArch() == llvm::Triple::x86_64 ||
-      getTriple().getArch() == llvm::Triple::arm || getTriple().isWasm() ||
+      getTriple().getArch() == llvm::Triple::arm ||
+      getTriple().getArch() == llvm::Triple::thumb || getTriple().isWasm() ||
       getTriple().isAArch64() || getTriple().isRISCV() ||
       getTriple().isLoongArch64())
     Res |= SanitizerKind::CFIICall;

clang/test/Driver/fsanitize.c

@@ -611,6 +611,8 @@
 // RUN: %clang --target=arm-linux-gnu -fvisibility=hidden -fsanitize=cfi -flto -resource-dir=%S/Inputs/resource_dir -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI
 // RUN: %clang --target=aarch64-linux-gnu -fvisibility=hidden -fsanitize=cfi -flto -resource-dir=%S/Inputs/resource_dir -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI
 // RUN: %clang --target=arm-linux-android -fvisibility=hidden -fsanitize=cfi -flto -resource-dir=%S/Inputs/resource_dir -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI
+// RUN: %clang --target=arm-none-eabi -fvisibility=hidden -fsanitize=cfi -flto -resource-dir=%S/Inputs/resource_dir -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI
+// RUN: %clang --target=thumb-none-eabi -fvisibility=hidden -fsanitize=cfi -flto -resource-dir=%S/Inputs/resource_dir -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI
 // RUN: %clang --target=aarch64-linux-android -fvisibility=hidden -fsanitize=cfi -flto -resource-dir=%S/Inputs/resource_dir -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI
 // RUN: %clang --target=aarch64_be -fvisibility=hidden -fsanitize=cfi -flto -resource-dir=%S/Inputs/resource_dir -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI
 // RUN: %clang --target=riscv32 -fvisibility=hidden -fsanitize=cfi -flto -resource-dir=%S/Inputs/resource_dir -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI