fix corner case in inline (#4320)

fixes #4319

lib/compress.js

@@ -4612,7 +4612,9 @@ merge(Compressor.prototype, {
                 for (var j = 0; j < len; j++) {
                     var arg = call.args[j];
                     if (!(arg instanceof AST_SymbolRef)) break;
-                    if (arg.definition() !== self.argnames[j].definition()) break;
+                    var argname = self.argnames[j];
+                    if (!(argname instanceof AST_SymbolFunarg)) break;
+                    if (arg.definition() !== argname.definition()) break;
                 }
                 if (j < len) break;
                 for (; j < call.args.length; j++) {

test/compress/destructured.js

@@ -1684,3 +1684,29 @@ issue_4315: {
     expect_stdout: "PASS"
     node_version: ">=6"
 }
+
+issue_4319: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        function f(a) {
+            while (!a);
+        }
+        console.log(function({}) {
+            return f(console);
+        }(0));
+    }
+    expect: {
+        function f(a) {
+            while (!a);
+        }
+        console.log(function({}) {
+            return f(console);
+        }(0));
+    }
+    expect_stdout: "undefined"
+    node_version: ">=6"
+}