compiler: Use backend interface for temporary reference expressions.

	* go-gcc.cc (Backend::convert_expression): New function.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@203209 138bc75d-0d04-0410-961f-82ee72b054a4
reflect: Fix calling Interface method on value created by MakeFunc.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@203212 138bc75d-0d04-0410-961f-82ee72b054a4