fix corner case in inline (#5257)

fixes #5256

lib/compress.js

@@ -12937,9 +12937,7 @@ Compressor.prototype.compress = function(node) {
             if (!fn.variables.all(function(def, name) {
                 if (in_loop) in_loop.push(def);
                 if (!defined.has(name) && !names.has(name)) return true;
-                if (name != "arguments") return false;
-                if (scope.uses_arguments) return false;
-                return def.references.length == def.replaced;
+                return !arrow && name == "arguments" && def.orig.length == 1;
             })) return;
             if (in_loop && in_loop.length > 0 && is_reachable(fn, in_loop)) return;
             var simple_argnames = true;

test/compress/default-values.js

@@ -2092,3 +2092,24 @@ issue_5246_3: {
     expect_stdout: "undefined"
     node_version: ">=6"
 }
+
+issue_5256: {
+    options = {
+        inline: true,
+    }
+    input: {
+        (function(arguments = console.log) {
+            console;
+        })();
+        console.log(typeof arguments);
+    }
+    expect: {
+        // Syntax error on Node.js v6
+        (function(arguments = console.log) {
+            console;
+        })();
+        console.log(typeof arguments);
+    }
+    expect_stdout: "undefined"
+    node_version: ">=8"
+}