re PR target/70296 (Incorrect handling of vector X; if X is function-like macro)

re PR target/70296 (Incorrect handling of vector X; if X is function-like macro)

	PR target/70296
	* include/cpplib.h (cpp_fun_like_macro_p): New prototype.
	* macro.c (cpp_fun_like_macro_p): New function.

	* config/rs6000/rs6000-c.c (rs6000_macro_to_expand): If IDENT is
	function-like macro, peek following token(s) if it is followed
	by CPP_OPEN_PAREN token with optional padding in between, and
	if not, don't treat it like a macro.

	* gcc.target/powerpc/altivec-36.c: New test.

From-SVN: r234371