re PR c++/10931 (valid conversion static_cast<const unsigned int&>(lvalue-of-type...

re PR c++/10931 (valid conversion static_cast<const unsigned int&>(lvalue-of-type-int) is rejected)

	PR c++/10931
	* g++.dg/expr/static_cast1.C: New test.

	PR c++/10931
	* call.c (convert_like): Pass issue_conversion_warnings.
	(convert_like_with_context): Likewise.
	(convert_like_real): Add issue_conversion_warnings parameter.
	(perform_direct_initialization_if_possible): New function.
	* cp-tree.h (perform_direct_initialization_if_possible): Declare it.
	* typeck.c (check_for_casting_away_constness): New function.
	(build_static_cast): Rewrite.

From-SVN: r68506