HIP supports compiling kernels from assembly into exec.
The device assembly needs to be compiled into a fat binary
object. This device object is embedded into a host object using
llvm-mc directives. Then, any host linker may link the host and
device objects together into an executable. A README is added.
Change-Id: I59d3a8b5363073810ffc3aa0d57f21b0df272369