[libc] Don't rely on LIBC_HAS_SANITIZER when enabling null checks. (#150341)

LIBC_HAS_SANITIZER (which is defined if ASan, MSan, or UBSan is enabled)
is currently used to implicitly disable null checks, normally enabled
via LIBC_ADD_NULL_CHECKS config value. Remove this condition, and rely
purely on the config value instead:

* LIBC_HAS_SANITIZER will be true even for UBSan modes which doesn't
rely on null checks at all (e.g. -fsanitize=alignment)
* null checks today (implemented via __builtin_trap) should function
normally today even when sanitizer is enabled - trap is still a trap
* tests have been migrated to WITH_SIGNAL(-1) which doesn't prescript a
particular signal / exit-code, and thus should pass even if sanitizers
override the default ones.

0 files changed, 0 insertions, 0 deletions