ShrinkWrap: Add skipFunction() call

ShrinkWrapping is a performance optimization that can safely be skipped,
so we can add `if (!skipFunction()) return;`

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303197 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed