rs6000.c (rs6000_mixed_function_arg): Rewrite.

rs6000.c (rs6000_mixed_function_arg): Rewrite.

	* config/rs6000/rs6000.c (rs6000_mixed_function_arg): Rewrite.
	(function_arg): Use rs6000_arg_size rather than CLASS_MAX_NREGS in
	calculating gpr size for altivec.  Simplify and correct
	rs6000_mixed_function_arg calls.  Call rs6000_mixed_function_arg
	for ABI_V4 gpr case too.  Fix off-by-one error in long double
	reg test.  Generate the correct PARALLEL to handle long double
	for ABI_AIX 32-bit.  Use this for -m32 -mpowerpc64 fpr case too.
	(function_arg_partial_nregs): Align before calculating regs left.
	Don't return info on partial fprs when we need info on gprs.
	Correct long double fpr off-by-one error.

From-SVN: r83951