Turn on Unique Internal Names for AFDO

AutoFDO uses a function’s symbol name to look up profile data but
functions with internal linkages do not have globally unique
identifiers. This can lead to name conflicts leading to missing profiles
and performance. We are enabling compiler option
-funique-internal-linkage-names for AFDO builds that will uniquefy
internal linkage symbols making this problem go away.

This CL might regress the performance due to mismatched profiles. It
will recover once we update the profiles.

Test: presubmit
Bug: 218448389
Change-Id: I92a2b6f72b52faab79aec9148f1962111bad7232