jscript: Use bytecode for null literal.

dlls/jscript/compile.c

@@ -179,6 +179,8 @@ static HRESULT compile_literal(compiler_ctx_t *ctx, literal_expression_t *expr)
         return push_instr_double(ctx, OP_double, literal->u.dval);
     case LT_INT:
         return push_instr_int(ctx, OP_int, literal->u.lval);
+    case LT_NULL:
+        return push_instr(ctx, OP_null);
     case LT_STRING:
         return push_instr_str(ctx, OP_str, literal->u.wstr);
     default:

dlls/jscript/engine.c

@@ -1724,6 +1724,17 @@ HRESULT identifier_expression_eval(script_ctx_t *ctx, expression_t *_expr, DWORD
     return hres;
 }
 
+/* ECMA-262 3rd Edition    7.8.1 */
+HRESULT interp_null(exec_ctx_t *ctx)
+{
+    VARIANT v;
+
+    TRACE("\n");
+
+    V_VT(&v) = VT_NULL;
+    return stack_push(ctx, &v);
+}
+
 /* ECMA-262 3rd Edition    7.8.2 */
 HRESULT interp_bool(exec_ctx_t *ctx)
 {

dlls/jscript/engine.h

@@ -51,6 +51,7 @@ typedef struct _func_stack {
     X(int, 1, ARG_INT)                            \
     X(neg, 1, 0)                                  \
     X(neq2, 1, 0)                                 \
+    X(null, 1, 0)                                 \
     X(str, 1, 0)                                  \
     X(tonum, 1, 0)                                \
     X(tree, 1, ARG_EXPR)                          \