rs6000.c (function_arg_boundary): Always align AltiVec vectors.

rs6000.c (function_arg_boundary): Always align AltiVec vectors.

	* config/rs6000/rs6000.c (function_arg_boundary): Always align
	AltiVec vectors.
	(function_arg_advance): Pass TARGET_32BIT -mabi=no-altivec AltiVec
	vectors by refererence.  Align the same for TARGET_64BIT to a 16
	byte boundary.  Remove useless code.  Add function comment.
	(function_arg): Similarly.  Move gpr rs6000_mixed_function_arg
	call to where it belongs.
	(function_arg_partial_nregs): Return true for all TARGET_32BIT
	-mabi=no-altivec AltiVec vectors.  Fix debug output.
	(rs6000_va_arg): Adjust for AltiVec change.

From-SVN: r81666