Remove libhsail-rt.

ChangeLog:

	* Makefile.def: Remove libhsail-rt.
	* Makefile.in: Likewise.
	* configure.ac: Likewise.
	* configure: Regenerate.
	* libhsail-rt/ChangeLog: Removed.
	* libhsail-rt/Makefile.am: Removed.
	* libhsail-rt/Makefile.in: Removed.
	* libhsail-rt/README: Removed.
	* libhsail-rt/aclocal.m4: Removed.
	* libhsail-rt/configure: Removed.
	* libhsail-rt/configure.ac: Removed.
	* libhsail-rt/configure.tgt: Removed.
	* libhsail-rt/include/internal/fibers.h: Removed.
	* libhsail-rt/include/internal/phsa-queue-interface.h: Removed.
	* libhsail-rt/include/internal/phsa-rt.h: Removed.
	* libhsail-rt/include/internal/workitems.h: Removed.
	* libhsail-rt/rt/arithmetic.c: Removed.
	* libhsail-rt/rt/atomics.c: Removed.
	* libhsail-rt/rt/bitstring.c: Removed.
	* libhsail-rt/rt/fbarrier.c: Removed.
	* libhsail-rt/rt/fibers.c: Removed.
	* libhsail-rt/rt/fp16.c: Removed.
	* libhsail-rt/rt/misc.c: Removed.
	* libhsail-rt/rt/multimedia.c: Removed.
	* libhsail-rt/rt/queue.c: Removed.
	* libhsail-rt/rt/sat_arithmetic.c: Removed.
	* libhsail-rt/rt/segment.c: Removed.
	* libhsail-rt/rt/workitems.c: Removed.
	* libhsail-rt/target-config.h.in: Removed.

contrib/ChangeLog:

	* gcc_update: Remove libhsail-rt folder.
	* update-copyright.py: Likewise.