amdgcn: Add builtins for vectorized native versions of abs, floorf and floor

2022-11-08  Kwok Cheung Yeung  <kcy@codesourcery.com>

	gcc/
	* config/gcn/gcn-builtins.def (FABSV, FLOORVF, FLOORV): New builtins.
	* config/gcn/gcn.cc (gcn_expand_builtin_1): Expand GCN_BUILTIN_FABSV,
	GCN_BUILTIN_FLOORVF and GCN_BUILTIN_FLOORV.

	gcc/testsuite/
	* gcc.target/gcn/math-builtins-1.c: New test.