config.gcc (powerpc*-*-linux*): Add powerpc*-*-linux*ppc476* variant.

	* config.gcc (powerpc*-*-linux*): Add powerpc*-*-linux*ppc476* variant.
	* config/rs6000/476.h: New file.
	* config/rs6000/476.opt: Likewise.
	* config/rs6000/rs6000.h (TARGET_LINK_STACK): New define.
	(SET_TARGET_LINK_STACK): Likewise.
	(TARGET_ASM_CODE_END): Define.
	* config/rs6000/rs6000.c (rs6000_option_override_internal): Enable
	TARGET_LINK_STACK for -mtune=476 and -mtune=476fp.
	(rs6000_legitimize_tls_address): Emit the link stack preserving GOT
	code if TARGET_LINK_STACK.
	(rs6000_emit_load_toc_table): Likewise.
	(output_function_profiler): Likewise
	(macho_branch_islands): Likewise
	(machopic_output_stub): Likewise
	(get_ppc476_thunk_name): New function.
	(rs6000_code_end): Likewise.
	* config/rs6000/rs6000.md (load_toc_v4_PIC_1, load_toc_v4_PIC_1b):
	Convert to a define_expand.
	(load_toc_v4_PIC_1_normal): New define_insn.
	(load_toc_v4_PIC_1_476): Likewise.
	(load_toc_v4_PIC_1b_normal): Likewise.
	(load_toc_v4_PIC_1b_476): Likewise.

From-SVN: r180741