gcc/ChangeLog:

2018-04-13  Kelvin Nilsen  <kelvin@gcc.gnu.org>

	* config/rs6000/rs6000-protos.h (rs6000_builtin_is_supported_p):
	New prototype.
	* config/rs6000/rs6000-c.c (altivec_resolve_overloaded_builtin):
	Add note to error message to explain internal mapping of overloaded
	built-in function name to non-overloaded built-in function name.
	* config/rs6000/rs6000.c (rs6000_builtin_is_supported_p): New
	function.

gcc/testsuite/ChangeLog:

2018-04-13  Kelvin Nilsen  <kelvin@gcc.gnu.org>

	* gcc.target/powerpc/bfp/scalar-extract-sig-5.c: Simplify to
	prevent cascading of errors and change expected error message.
	* gcc.target/powerpc/bfp/scalar-test-neg-4.c: Restrict this test
	to 64-bit targets.
	* gcc.target/powerpc/bfp/scalar-test-data-class-8.c: Likewise.
	* gcc.target/powerpc/bfp/scalar-test-data-class-9.c: Likewise.
	* gcc.target/powerpc/bfp/scalar-test-data-class-10.c: Likewise.
	* gcc.target/powerpc/bfp/scalar-insert-exp-11.c: Change expected
	error message.
	* gcc.target/powerpc/bfp/scalar-extract-exp-5.c: Likewise.

From-SVN: r259442