re PR c/80116 (Warn about macros expanding to multiple statements)

re PR c/80116 (Warn about macros expanding to multiple statements)

	PR c/80116
	* c-common.h (warn_for_multistatement_macros): Declare.
	* c-warn.c: Include "c-family/c-indentation.h".
	(warn_for_multistatement_macros): New function.
	* c.opt (Wmultistatement-macros): New option.
	* c-indentation.c (guard_tinfo_to_string): No longer static.
	Change the parameter type to "enum rid".  Handle RID_SWITCH.
	* c-indentation.h (guard_tinfo_to_string): Declare.

	* c-parser.c (c_parser_if_body): Set the location of the
	body of the conditional after parsing all the labels.  Call
	warn_for_multistatement_macros.
	(c_parser_else_body): Likewise.
	(c_parser_switch_statement): Likewise.
	(c_parser_while_statement): Likewise.
	(c_parser_for_statement): Likewise.
	(c_parser_statement): Add a default argument.  Save the location
	after labels have been parsed.
	(c_parser_c99_block_statement): Likewise.

	* parser.c (cp_parser_statement): Add a default argument.  Save the
	location of the expression-statement after labels have been parsed.
	(cp_parser_implicitly_scoped_statement): Set the location of the
	body of the conditional after parsing all the labels.  Call
	warn_for_multistatement_macros.
	(cp_parser_already_scoped_statement): Likewise.

	* doc/invoke.texi: Document -Wmultistatement-macros.

	* c-c++-common/Wmultistatement-macros-1.c: New test.
	* c-c++-common/Wmultistatement-macros-2.c: New test.
	* c-c++-common/Wmultistatement-macros-3.c: New test.
	* c-c++-common/Wmultistatement-macros-4.c: New test.
	* c-c++-common/Wmultistatement-macros-5.c: New test.
	* c-c++-common/Wmultistatement-macros-6.c: New test.
	* c-c++-common/Wmultistatement-macros-7.c: New test.
	* c-c++-common/Wmultistatement-macros-8.c: New test.
	* c-c++-common/Wmultistatement-macros-9.c: New test.
	* c-c++-common/Wmultistatement-macros-10.c: New test.
	* c-c++-common/Wmultistatement-macros-11.c: New test.

From-SVN: r249643