PR c++/11295
	* doc/extend.texi (Statement Expressions): Document C++ semantics.
cp:
	PR c++/11295
	* cp-tree.h (tubst_flags_t): Add tf_stmt_expr_cmpd,
	tf_stmt_expr_body.
	(finish_stmt_expr_expr): Declare.
	* parser.c (cp_parser_primary_expression): Tell
	cp_parser_compount_statement that it is a statement expression.
	(cp_parser_statement, cp_parser_labeled_statement,
	cp_parser_compound_statement, cp_parser_statement_seq_opt): Add
	in_statement_expr_p parameter.
	(cp_parser_expression_statement): Likewise. Call
	finish_stmt_expr_expr for final expression of a statement
	expression.
	(cp_parser_for_init_statement,
	cp_parser_implicitly_scoped_statement,
	cp_parser_already_scoped_statement, cp_parser_function_definition,
	cp_parser_try_block, cp_parser_handled): Adjust.
	* pt.c (tsubst_copy) <STMT_EXPR case>: Pass tf_stmt_expr.
	(tsubst_expr): Process tf_stmt_expr and tf_stmt_exprs flags.
	(tsubst_expr) <EXPR_STMT case>: Check tf_stmt_exprs flag.
	* semantics.c (finish_expr_stmt): Do not deal with statement
	expressions.
	(begin_stmt_expr): Clear last_expr_type.
	(finish_stmt_expr_expr): New.
	(finish_stmt_expr): Process the value expression.
testsuite:
	PR c++/11295
	* g++.dg/ext/stmtexpr1.C: New test.

From-SVN: r70043