compiler_rt: Import latest changes on int_lib.h

Imported from the LLVM compiler_rt library on master branch as of
30 Oct 2018 (SVN revision: r345645).

Change-Id: I058cfb5894daf1d12e1ef971c0ba36b0aa089be5
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
1 file changed