* trans.c (lvalue_required_p): Take base node directly instead
	of its parent.  Rename second parameter to 'gnu_type'.
	<N_Indexed_Component>: Return 0 if the node isn't the prefix.
	<N_Slice>: Likewise.
	(Identifier_to_gnu): Rename parent_requires_lvalue to require_lvalue.
	Adjust calls to lvalue_required_p.

From-SVN: r130626