[BuildLibCalls] Add noundef to the returned pointers of allocators and argument of free

This patch adds noundef to the returned pointers of allocators (malloc, calloc, ...)
and the pointer argument of free.
The returned pointer of allocators cannot be poison or (partially) undef.
Since the pointer that is given to free should precisely have zero offset,
it cannot be poison or (partially) undef too.

For the size arguments of allocators, noundef wasn't attached simply because
I wasn't sure whether attaching it is okay or not.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D87984