[LSan] Introduce a callback mechanism to allow adding data reachable from ThreadContexts to the frontier.
This mechanism is intended to provide a way to treat the `arg` pointer
of a created (but not yet started) thread as reachable. In future
patches this will be implemented in `GetAdditionalThreadContextPtrs`.
A separate implementation of `GetAdditionalThreadContextPtrs` exists
for ASan and LSan runtimes because they need to be implemented
differently in future patches.
rdar://problem/63537240
Differential Revision: https://reviews.llvm.org/D95183
GitOrigin-RevId: dd922bc2a62163cef442646974324943c551725e
4 files changed
