re PR c++/55742 (__attribute__ in class function declaration cause "prototype does not match" errors.)

	PR c++/55742
	* config/i386/i386.c (ix86_valid_target_attribute_inner_p): Diagnose
	invalid args instead of ICEing on it.
	(ix86_valid_target_attribute_tree): Return error_mark_node if
	ix86_valid_target_attribute_inner_p failed.
	(ix86_valid_target_attribute_p): Return false only if
	ix86_valid_target_attribute_tree returned error_mark_node.  Allow
	target("default") attribute.
	(sorted_attr_string): Change argument from const char * to tree,
	merge in all target attribute arguments rather than just one.
	Formatting fix.  Use XNEWVEC instead of xmalloc and XDELETEVEC
	instead of free.  Avoid using strcat.
	(ix86_mangle_function_version_assembler_name): Mangle
	target("default") as if no target attribute is present.  Adjust
	sorted_attr_string caller.  Avoid leaking memory.  Use XNEWVEC
	instead of xmalloc and XDELETEVEC instead of free.
	(ix86_function_versions): Don't return true if one of the decls
	doesn't have target attribute.  If they don't and one of the decls
	is DECL_FUNCTION_VERSIONED, report an error.  Adjust
	sorted_attr_string caller.  Use XDELETEVEC instead of free.
	(ix86_supports_function_versions): Remove.
	(make_name): Fix up formatting.
	(make_dispatcher_decl): Remove resolver_name and its initialization.
	Avoid leaking memory.
	(is_function_default_version): Return true if there is
	target("default") attribute rather than no target attribute at all.
	(make_resolver_func): Avoid leaking memory.
	(ix86_generate_version_dispatcher_body): Likewise.
	(TARGET_OPTION_SUPPORTS_FUNCTION_VERSIONS): Remove.
	* target.def (supports_function_versions): Remove.
	* doc/tm.texi.in (SUPPORTS_FUNCTION_VERSIONS): Remove.
	* doc/tm.texi: Regenerated.

	* c-common.c (handle_target_attribute): Revert 2012-12-26 change.

	* g++.dg/mv1.C: Moved to...
	* g++.dg/ext/mv1.C: ... here.  Adjust test.
	* g++.dg/mv2.C: Moved to...
	* g++.dg/ext/mv2.C: ... here.  Adjust test.
	* g++.dg/mv3.C: Moved to...
	* g++.dg/ext/mv3.C: ... here.
	* g++.dg/mv4.C: Moved to...
	* g++.dg/ext/mv4.C: ... here.
	* g++.dg/mv5.C: Moved to...
	* g++.dg/ext/mv5.C: ... here.  Adjust test.
	* g++.dg/mv6.C: Moved to...
	* g++.dg/ext/mv6.C: ... here.  Adjust test.
	* g++.dg/ext/mv7.C: New test.
	* g++.dg/ext/mv8.C: New test.
	* g++.dg/ext/mv9.C: New test.
	* g++.dg/ext/mv10.C: New test.
	* g++.dg/ext/mv11.C: New test.

From-SVN: r195584