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

[Dmitry Vyukov via cfe-commits]

================
@@ -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
----------------
dvyukov wrote:

I wouldn't explain this in terms of "landing pads", etc, only 0.01% of engineers understand this terminology.

Uninstrumented code also does not call function entry hooks, so perhaps there is nothing to cleanup for uninstrumented code?

Are there any known issues reported for exceptions? I am not sure what we should say. We could reflect the actual state of our knowledge -- "unknown/not well tested". But w/o spelling any concrete facts this does not look too useful for end users.


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