[sanitizer] Don't TestPTrace() if SPARC; don't give up if internal_fork() fails (#152072)
Fixes corner cases of https://github.com/llvm/llvm-project/pull/151406:
- Don't run TestPTrace() on SPARC, because internal_fork() on SPARC
actually calls __fork(). We can't safely __fork(), because it's possible
seccomp has been configured to disallow fork() but allow clone().
- if internal_fork() fails for whatever reason, we shouldn't give up. It
is strictly worse to give up early than to attempt StopTheWorld.
Also updates some comments/TODOs.
GitOrigin-RevId: 435b8b51dc7e236d3940efe4b94104338dbac0e8
1 file changed
