hwasan: Read shadow address from ifunc if we don't need a frame record.

This saves a cbz+cold call in the interceptor ABI, as well as a realign
in both ABIs, trading off a dcache entry against some branch predictor
entries and some code size.

Unfortunately the functionality is hidden behind a flag because ifunc is
known to be broken on static binaries on Android.

Differential Revision: https://reviews.llvm.org/D57084

Change-Id: I71c1d6a84294504a429fb9e725da471bd9bfc10b
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351989 91177308-0d34-0410-b5e6-96231b3b80d8