Patch to remove useless non_lvalue calls

[Tom Tromey]

>>>>> "Joseph" == Joseph S Myers <jsm@polyomino.org.uk> writes:

Joseph> It would be possible to hook fold so that front ends not
Joseph> needing non_lvalue to do anything don't get the unnecessary
Joseph> NON_LVALUE_EXPRs generated, or if C++ (and I don't know about Java)
Joseph> can be fixed to track lvalueness internally then we can get rid of
Joseph> NON_LVALUE_EXPR.

I don't think gcj generates or uses NON_LVALUE_EXPR.  It is only
mentioned in two places, and in both situations it is just treated
identically to some other tree code.

Tom