[ASan] Clean up leftovers from assembly instrumentation helpers

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@212471 91177308-0d34-0410-b5e6-96231b3b80d8
[Sanitizer] Move test for malloc/free hooks under test/sanitizer_common

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@212474 91177308-0d34-0410-b5e6-96231b3b80d8