Mark BumpPtrAllocator::Allocate as returning a noalias pointer.

The GCC attribute is curiously named 'malloc', but I think it's better
to use LLVM terminology for the wrapper macro.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234121 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed