Refactor the alloc entry point generation code.

Move the x86/x86-64 specific alloc entrypoint generation code to a macro
GENERATE_ALLOC_ENTRYPOINTS_FOR_EACH_ALLOCATOR in a common file to remove
duplication.

This will make it easier to selectively add more hand-written assembly
allocation fast path code.

Rename RETURN_IF_RESULT_IS_NON_ZERO to
RETURN_IF_RESULT_IS_NON_ZERO_OR_DELIVER in the x86/x86_64 files to match
the other architectures.

Bug: 9986565
Change-Id: I56f33b790f94db68891db8a2f42e9231d1770eef
3 files changed