re PR target/65810 (powerpc64 alignment of r2 insufficient for loading long-double...

re PR target/65810 (powerpc64 alignment of r2 insufficient for loading long-double constants)

	PR target/65810
	* config/rs6000/rs6000.c (POWERPC64_TOC_POINTER_ALIGNMENT): Define.
	(offsettable_ok_by_alignment): Use minimum of decl and toc
	pointer alignment.  Replace dead code with assertion.
	(use_toc_relative_ref): Add mode arg.  Return false in -mcmodel=medium
	case if size exceeds toc pointer alignment.
	(rs6000_legitimize_reload_address): Update use_toc_relative_ref call.
	(rs6000_emit_move): Likewise.
	* configure.ac: Add linker toc pointer alignment check.
	* configure: Regenerate.
	* config.in: Regenerate.

From-SVN: r222498