amdgcn: implement vector div and mod libfuncs

Also divmod, but only for scalar modes, for now (because there are no complex
int vectors yet).

gcc/ChangeLog:

	* config/gcn/gcn.cc (gcn_expand_divmod_libfunc): New function.
	(gcn_init_libfuncs): Add div and mod functions for all modes.
	Add placeholders for divmod functions.
	(TARGET_EXPAND_DIVMOD_LIBFUNC): Define.

libgcc/ChangeLog:

	* config/gcn/lib2-divmod-di.c: Reimplement like lib2-divmod.c.
	* config/gcn/lib2-divmod.c: Likewise.
	* config/gcn/lib2-gcn.h: Add new types and prototypes for all the
	new vector libfuncs.
	* config/gcn/t-amdgcn: Add new files.
	* config/gcn/amdgcn_veclib.h: New file.
	* config/gcn/lib2-vec_divmod-di.c: New file.
	* config/gcn/lib2-vec_divmod-hi.c: New file.
	* config/gcn/lib2-vec_divmod-qi.c: New file.
	* config/gcn/lib2-vec_divmod.c: New file.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/predcom-2.c: Avoid vectors on amdgcn.
	* gcc.dg/unroll-8.c: Likewise.
	* gcc.dg/vect/slp-26.c: Change expected results on amdgdn.
	* lib/target-supports.exp
	(check_effective_target_vect_int_mod): Add amdgcn.
	(check_effective_target_divmod): Likewise.
	* gcc.target/gcn/simd-math-3-16.c: New test.
	* gcc.target/gcn/simd-math-3-2.c: New test.
	* gcc.target/gcn/simd-math-3-32.c: New test.
	* gcc.target/gcn/simd-math-3-4.c: New test.
	* gcc.target/gcn/simd-math-3-8.c: New test.
	* gcc.target/gcn/simd-math-3-char-16.c: New test.
	* gcc.target/gcn/simd-math-3-char-2.c: New test.
	* gcc.target/gcn/simd-math-3-char-32.c: New test.
	* gcc.target/gcn/simd-math-3-char-4.c: New test.
	* gcc.target/gcn/simd-math-3-char-8.c: New test.
	* gcc.target/gcn/simd-math-3-char-run-16.c: New test.
	* gcc.target/gcn/simd-math-3-char-run-2.c: New test.
	* gcc.target/gcn/simd-math-3-char-run-32.c: New test.
	* gcc.target/gcn/simd-math-3-char-run-4.c: New test.
	* gcc.target/gcn/simd-math-3-char-run-8.c: New test.
	* gcc.target/gcn/simd-math-3-char-run.c: New test.
	* gcc.target/gcn/simd-math-3-char.c: New test.
	* gcc.target/gcn/simd-math-3-long-16.c: New test.
	* gcc.target/gcn/simd-math-3-long-2.c: New test.
	* gcc.target/gcn/simd-math-3-long-32.c: New test.
	* gcc.target/gcn/simd-math-3-long-4.c: New test.
	* gcc.target/gcn/simd-math-3-long-8.c: New test.
	* gcc.target/gcn/simd-math-3-long-run-16.c: New test.
	* gcc.target/gcn/simd-math-3-long-run-2.c: New test.
	* gcc.target/gcn/simd-math-3-long-run-32.c: New test.
	* gcc.target/gcn/simd-math-3-long-run-4.c: New test.
	* gcc.target/gcn/simd-math-3-long-run-8.c: New test.
	* gcc.target/gcn/simd-math-3-long-run.c: New test.
	* gcc.target/gcn/simd-math-3-long.c: New test.
	* gcc.target/gcn/simd-math-3-run-16.c: New test.
	* gcc.target/gcn/simd-math-3-run-2.c: New test.
	* gcc.target/gcn/simd-math-3-run-32.c: New test.
	* gcc.target/gcn/simd-math-3-run-4.c: New test.
	* gcc.target/gcn/simd-math-3-run-8.c: New test.
	* gcc.target/gcn/simd-math-3-run.c: New test.
	* gcc.target/gcn/simd-math-3-short-16.c: New test.
	* gcc.target/gcn/simd-math-3-short-2.c: New test.
	* gcc.target/gcn/simd-math-3-short-32.c: New test.
	* gcc.target/gcn/simd-math-3-short-4.c: New test.
	* gcc.target/gcn/simd-math-3-short-8.c: New test.
	* gcc.target/gcn/simd-math-3-short-run-16.c: New test.
	* gcc.target/gcn/simd-math-3-short-run-2.c: New test.
	* gcc.target/gcn/simd-math-3-short-run-32.c: New test.
	* gcc.target/gcn/simd-math-3-short-run-4.c: New test.
	* gcc.target/gcn/simd-math-3-short-run-8.c: New test.
	* gcc.target/gcn/simd-math-3-short-run.c: New test.
	* gcc.target/gcn/simd-math-3-short.c: New test.
	* gcc.target/gcn/simd-math-3.c: New test.
	* gcc.target/gcn/simd-math-4-char-run.c: New test.
	* gcc.target/gcn/simd-math-4-char.c: New test.
	* gcc.target/gcn/simd-math-4-long-run.c: New test.
	* gcc.target/gcn/simd-math-4-long.c: New test.
	* gcc.target/gcn/simd-math-4-run.c: New test.
	* gcc.target/gcn/simd-math-4-short-run.c: New test.
	* gcc.target/gcn/simd-math-4-short.c: New test.
	* gcc.target/gcn/simd-math-4.c: New test.
	* gcc.target/gcn/simd-math-5-16.c: New test.
	* gcc.target/gcn/simd-math-5-32.c: New test.
	* gcc.target/gcn/simd-math-5-4.c: New test.
	* gcc.target/gcn/simd-math-5-8.c: New test.
	* gcc.target/gcn/simd-math-5-char-16.c: New test.
	* gcc.target/gcn/simd-math-5-char-32.c: New test.
	* gcc.target/gcn/simd-math-5-char-4.c: New test.
	* gcc.target/gcn/simd-math-5-char-8.c: New test.
	* gcc.target/gcn/simd-math-5-char-run-16.c: New test.
	* gcc.target/gcn/simd-math-5-char-run-32.c: New test.
	* gcc.target/gcn/simd-math-5-char-run-4.c: New test.
	* gcc.target/gcn/simd-math-5-char-run-8.c: New test.
	* gcc.target/gcn/simd-math-5-char-run.c: New test.
	* gcc.target/gcn/simd-math-5-char.c: New test.
	* gcc.target/gcn/simd-math-5-long-16.c: New test.
	* gcc.target/gcn/simd-math-5-long-32.c: New test.
	* gcc.target/gcn/simd-math-5-long-4.c: New test.
	* gcc.target/gcn/simd-math-5-long-8.c: New test.
	* gcc.target/gcn/simd-math-5-long-run-16.c: New test.
	* gcc.target/gcn/simd-math-5-long-run-32.c: New test.
	* gcc.target/gcn/simd-math-5-long-run-4.c: New test.
	* gcc.target/gcn/simd-math-5-long-run-8.c: New test.
	* gcc.target/gcn/simd-math-5-long-run.c: New test.
	* gcc.target/gcn/simd-math-5-long.c: New test.
	* gcc.target/gcn/simd-math-5-run-16.c: New test.
	* gcc.target/gcn/simd-math-5-run-32.c: New test.
	* gcc.target/gcn/simd-math-5-run-4.c: New test.
	* gcc.target/gcn/simd-math-5-run-8.c: New test.
	* gcc.target/gcn/simd-math-5-run.c: New test.
	* gcc.target/gcn/simd-math-5-short-16.c: New test.
	* gcc.target/gcn/simd-math-5-short-32.c: New test.
	* gcc.target/gcn/simd-math-5-short-4.c: New test.
	* gcc.target/gcn/simd-math-5-short-8.c: New test.
	* gcc.target/gcn/simd-math-5-short-run-16.c: New test.
	* gcc.target/gcn/simd-math-5-short-run-32.c: New test.
	* gcc.target/gcn/simd-math-5-short-run-4.c: New test.
	* gcc.target/gcn/simd-math-5-short-run-8.c: New test.
	* gcc.target/gcn/simd-math-5-short-run.c: New test.
	* gcc.target/gcn/simd-math-5-short.c: New test.
	* gcc.target/gcn/simd-math-5.c: New test.