[llvm-branch-commits] [lsan] Process non-suspended threads (PR #112807)

[Vitaly Buka via llvm-branch-commits]

https://github.com/vitalybuka created https://github.com/llvm/llvm-project/pull/112807

For such threads we have no registers, so no exact
stack range, and no guaranties that stack is mapped
at all.

To avoid crashes on unmapped memory,
 `MemCpyAccessible` copies intersting range into
 temporarily buffer, and we search for pointers there.