[lldb][test][NFC] TestBreakpointSetRestart.py: split up assertion to determine which check specifically fails in CI

This test consistently fails on the public macOS ASAN CI (and isn't
reproducible locally):
```
FAIL: test_breakpoint_set_restart_dwarf
(TestBreakpointSetRestart.BreakpointSetRestart)
----------------------------------------------------------------------
Traceback (most recent call last):
  File
"/Users/ec2-user/jenkins/workspace/llvm.org/lldb-cmake-sanitized/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py",
line 1756, in test_method
    return attrvalue(self)
  File
"/Users/ec2-user/jenkins/workspace/llvm.org/lldb-cmake-sanitized/llvm-project/lldb/packages/Python/lldbsuite/test/decorators.py",
line 150, in wrapper
    return func(*args, **kwargs)
  File
"/Users/ec2-user/jenkins/workspace/llvm.org/lldb-cmake-sanitized/llvm-project/lldb/test/API/functionalities/breakpoint/breakpoint_set_restart/TestBreakpointSetRestart.py",
line 36, in test_breakpoint_set_restart
    self.assertTrue(bp.IsValid() and bp.GetNumLocations() == 1,
VALID_BREAKPOINT)
AssertionError: False is not true : Got a valid breakpoint
```

From this error we're not quite sure what about the breakpoint here is
the problem.

This patch splits up the assertion to narrow down the issue.

Author: Michael137

lldb/test/API/functionalities/breakpoint/breakpoint_set_restart/TestBreakpointSetRestart.py

@@ -33,7 +33,8 @@ def test_breakpoint_set_restart(self):
         bp = target.BreakpointCreateBySourceRegex(
             self.BREAKPOINT_TEXT, lldb.SBFileSpec("main.cpp")
         )
-        self.assertTrue(bp.IsValid() and bp.GetNumLocations() == 1, VALID_BREAKPOINT)
+        self.assertTrue(bp.IsValid(), VALID_BREAKPOINT)
+        self.assertEqual(bp.GetNumLocations(), 1, VALID_BREAKPOINT)
 
         while self.dbg.GetListener().WaitForEvent(2, event):
             if lldb.SBProcess.GetStateFromEvent(