[asan] add a feature to detect new-delete-size-mismatch (when used with -Xclang -fsized-deallocation). Not yet on Mac. Also, remove some unused code.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@214296 91177308-0d34-0410-b5e6-96231b3b80d8