tccgen.c: Try to make sizeof(!x) work.

tests/tests2/27_sizeof.*: Add test.

tccgen.c

@@ -3877,12 +3877,10 @@ ST_FUNC void unary(void)
             vtop->c.i = !vtop->c.i;
         } else if ((vtop->r & VT_VALMASK) == VT_CMP)
             vtop->c.i ^= 1;
-        else if (!nocode_wanted) {
+        else {
             save_regs(1);
             vseti(VT_JMP, gvtst(1, 0));
         }
-        else
-            vtop--;
         break;
     case '~':
         next();

tests/tests2/27_sizeof.c

@@ -10,6 +10,8 @@ int main()
    printf("%d\n", sizeof(b));
    printf("%d\n", sizeof(c));
 
+   printf("%d\n", sizeof(!a));
+
    return 0;
 }
 

tests/tests2/27_sizeof.expect

@@ -1,3 +1,4 @@
 1
 4
 8
+4