[clang] [clang][docs] Document ThreadSanitizer run-time flags and suppressions (PR #205761)

[Alexander Potapenko via cfe-commits]

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@@ -187,6 +198,24 @@ Limitations
   ``fsanitize=thread`` flag will cause Clang to act as though the ``-fPIE``
   flag had been supplied if compiling without ``-fPIC``, and as though the
   ``-pie`` flag had been supplied if linking an executable.
+* ThreadSanitizer does not support C++ exceptions. Programs relying heavily on
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ramosian-glider wrote:

I found https://github.com/llvm/llvm-project/issues/66537, but it's probably less of an exception handling problem. https://github.com/google/sanitizers/issues/485 is quite stale. There also are some Reddit/StackOverflow mentions of TSan not supporting them, but they don't provide any good evidence.

We could as well drop this bullet. My original intent was to reflect what was mentioned in https://github.com/google/sanitizers/wiki/ThreadSanitizerCppManual, but perhaps the status quo has changed.
We can revisit this when we start seeing bug reports.

https://github.com/llvm/llvm-project/pull/205761