rs6000: Separate shrink-wrapping for FPRs

This patch implements separate shrink-wrapping for the non-volatile
floating point registers (FPR14..FPR31).  It is pretty much exactly
analogous to the code for GPRs.


	* config/rs6000/rs6000.c (struct machine_function): Add field
	fpr_is_wrapped_separately.
	(rs6000_get_separate_components): Use 64 components.  Handle the
	new FPR components.
	(rs6000_components_for_bb): Handle the FPR components.
	(rs6000_emit_prologue_components): Handle the FPR components.
	(rs6000_emit_epilogue_components): Handle the FPR components.
	(rs6000_set_handled_components): Handle the FPR components.
	(rs6000_emit_prologue): Don't output prologue code for those FPRs
	that are already separately shrink-wrapped.
	(rs6000_emit_epilogue): Don't output epilogue code for those FPRs
	that are already separately shrink-wrapped.

From-SVN: r248256