Fix a bug for rL312641.

Fix a bug for rL312641.

rL312641 Allowed llvm.memcpy/memset/memmove to be tail calls when parent
function return the intrinsics's first argument. However on arm-none-eabi
platform, llvm.memcpy will be expanded to __aeabi_memcpy which doesn't
have return value. The fix is to check the libcall name after expansion
to match "memcpy/memset/memmove" before allowing those intrinsic to be
tail calls.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312799 91177308-0d34-0410-b5e6-96231b3b80d8