* typeck.c (build_binary_op): Fix pmf comparison logic.

From-SVN: r38637

gcc/testsuite/g++.old-deja/g++.other/pmf6.C

+// Test that we only call f once and that pointers to different subobjects
+// compare as different.
+
+struct A { void f() { } };
+struct B: public A { };
+struct C: public A { };
+struct D : public B, public C { };
+
+typedef void (B::*bp)();
+typedef void (C::*cp)();
+typedef void (D::*dp)();
+
+dp d1;
+
+int call;
+
+dp f () { ++call; return d1; }
+
+int main()
+{
+  bp b = &A::f;
+  cp c = &A::f;
+  d1 = b;
+  dp d2 = c;
+  return (f() == d2 || call != 1);
+}