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.