vbscript: Support VT_EMPTY in stack_pop_bool.

Signed-off-by: Jacek Caban <jacek@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

dlls/vbscript/interp.c

@@ -374,6 +374,7 @@ static int stack_pop_bool(exec_ctx_t *ctx, BOOL *b)
         *b = V_BOOL(val.v);
         break;
     case VT_NULL:
+    case VT_EMPTY:
         *b = FALSE;
         break;
     case VT_I2:

dlls/vbscript/tests/lang.vbs

@@ -329,6 +329,14 @@ end if
 while false
 wend
 
+if empty then
+   ok false, "if empty executed"
+end if
+
+while empty
+   ok false, "while empty executed"
+wend
+
 x = 0
 WHILE x < 3 : x = x + 1
 Wend