[asan] add option -asan-keep-uninstrumented-functions

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184927 91177308-0d34-0410-b5e6-96231b3b80d8
[asan] workaround for PR16277: don't instrument AllocaInstr with alignment more than the redzone size

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184928 91177308-0d34-0410-b5e6-96231b3b80d8