* c-typeck.c (pedantic_lvalue_warning): Deprecate compound
	expressions as lvalues.
	(internal_build_compound_expr): Remove special handling for
	non-pedantic case.
	* doc/extend.texi: Document that all extended lvalues are now
	deprecated.

testsuite:
	* gcc.dg/compound-lvalue-1.c: New test.
	* gcc.dg/c90-const-expr-2.c, gcc.dg/c99-const-expr-2.c: Remove
	some XFAILs.

From-SVN: r73352