[Issue 23700] New: compilable/test22842.c:64:24: error: expression in static assertion is not constant

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=23700

          Issue ID: 23700
           Summary: compilable/test22842.c:64:24: error: expression in
                    static assertion is not constant
           Product: D
           Version: D2
          Hardware: All
                OS: Linux
            Status: NEW
          Severity: major
          Priority: P1
         Component: dmd
          Assignee: nobody at puremagic.com
          Reporter: ibuclaw at gdcproject.org

When compiling the test with `gcc -std=c11 -fsyntax-only`

compilable/test22842.c:64:24: error: expression in static assertion is not
constant
   64 | _Static_assert(mint1() == -1, "1");
      |                ~~~~~~~~^~~~~
compilable/test22842.c: In function ‘mint3’:
compilable/test22842.c:80:18: warning: cast from pointer to integer of
different size [-Wpointer-to-int-cast]
   80 |     unsigned x = (unsigned)(p) & 1;
      |                  ^


Test content:
```
// https://issues.dlang.org/show_bug.cgi?id=22876

int mint1()
{
    int a = 0;
    // dmd gives 1, other compilers -1
    // bug disappears if the parentheses around (a) are removed
    return - (a) - 1;
}

_Static_assert(mint1() == -1, "1");
```

--