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

This is to get the __aeabi_llsr() builtin, which is required by a
subsequent patch that uses a logical right shift operator in AArch32.

Change-Id: I9884139a12855a8a87206fb572aaa7dd35582b09
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>