PR testsuite/43758
	* target.h (struct gcc_target): Add attribute_takes_identifier_p.
	* target_def.h (TARGET_ATTRIBUTE_TAKES_IDENTIFIER_P): Define.
	(TARGET_INITIALIZER): Use it.
	* c-common.c (attribute_takes_identifier_p): Call it.
	* c-common.h: Update prototype.
	* config/rs6000/rs6000.c (rs6000_attribute_takes_identifier_p): New.
	(TARGET_ATTRIBUTE_TAKES_IDENTIFIER_P): Define.

From-SVN: r159079