Compiler infinite loop with AutoFDO and GCOV #2172

@yabinc may be able to provide more info (such as what translation unit we saw this in, what the last known good LLVM SHA and first known bad LLVM SHA were).

In at least one of our kernel builds for Android, enabling GCOV caused the compiler to enter an infinite loop. We were able to quickly work around this by filtering the profile data for a few symbols, but I don't consider this a viable long term solution and worry that this might pop up again and not just for GCOV.