Bad codegen for comparison with postfix increment

[Paul Backus via D.gnu]

When the following program is compiled with GDC 14.1, the 
assertion fails:

    void main() {
        int d = 42;
        bool o = d > d++;
        assert(o == false);
    }
(Godbolt: https://d.godbolt.org/z/e63xbb9Td)

The assertion passes when the program is compiled with DMD 
2.108.0.

The same bug was recently reported for LDC: 
https://github.com/ldc-developers/ldc/issues/4651