fix corner case in inline (#5329)

fixes #5328

lib/compress.js

@@ -13170,9 +13170,11 @@ Compressor.prototype.compress = function(node) {
                 scope = scope.parent_scope;
             }
             if (!member(scope, compressor.stack)) return;
-            if (scope instanceof AST_Toplevel && fn.variables.size() > (arrow ? 0 : 1)) {
-                if (!compressor.toplevel.vars) return;
-                if (fn.functions.size() > 0 && !compressor.toplevel.funcs) return;
+            if (scope instanceof AST_Toplevel) {
+                if (fn.variables.size() > (arrow ? 0 : 1)) {
+                    if (!compressor.toplevel.vars) return;
+                    if (fn.functions.size() > 0 && !compressor.toplevel.funcs) return;
+                }
                 defined.set("arguments", true);
             }
             var async = is_async(fn);

test/compress/functions.js

@@ -8134,3 +8134,20 @@ issue_5316_2: {
     }
     expect_stdout: "PASS"
 }
+
+issue_5328: {
+    options = {
+        inline: true,
+    }
+    input: {
+        (function(arguments) {
+            console.log(Object.keys(arguments).join());
+        })(this);
+    }
+    expect: {
+        (function(arguments) {
+            console.log(Object.keys(arguments).join());
+        })(this);
+    }
+    expect_stdout: ""
+}