[Sanitizer] Fix sanitizer tests without reducing optimization levels
As discussed, these tests are compiled with optimization to mimic real
sanitizer usage .
Let's mark relevant functions with noinline so we can continue to
check against the stack traces in the report.
This reverts commit 04af72c5423eb5ff7c0deba2d08cb46d583bb9d4.
Differential Revision: https://reviews.llvm.org/D96357