type punned warns in tccgen

gistfile1.txt

```
tccgen.c: In function 'is_compatible_func':
tccgen.c:514:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
     if (FUNC_CALL(s1->r) != FUNC_CALL(s2->r))
     ^
tccgen.c:514:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
tccgen.c: In function 'parse_btype':
tccgen.c:1220:21: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
                     ad->aligned = FUNC_ALIGN(s->r);
                     ^
tccgen.c:1222:21: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
                     ad->func_call = FUNC_CALL(s->r);
                     ^
tccgen.c:1223:17: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
                 ad->packed |= FUNC_PACKED(s->r);
                 ^
tccgen.c: In function 'decl0':
tccgen.c:2818:22: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
                      && FUNC_CALL(type.ref->r) == FUNC_CDECL)
                      ^
tccgen.c:2819:25: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
                         FUNC_CALL(type.ref->r) = FUNC_CALL(r);
                         ^
tccgen.c:2823:25: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
                         FUNC_EXPORT(type.ref->r) = 1;
```