re PR c++/9440 (error message about "non-lvalue in unary '&'" when using ?: operator)

        PR c++/9440
        * call.c (build_conditional_expr): Use convert rather than an
        explicit NOP_EXPR.

From-SVN: r64651

gcc/testsuite/g++.dg/conversion/cond1.C

+// PR c++/9440
+ struct A {
+     explicit A(int = 0);
+     A(const A&);
+     operator int() const;
+ };
+ 
+ A
+ bar(bool b, const A& a)
+ {
+     return (b ? A() : a);
+ }