replace single-use class definitions (#2524)

fixes #2416

test/compress/reduce_vars.js

@@ -4849,7 +4849,7 @@ issue_2496: {
         new Foo("FAIL").run();
     }
     expect: {
-        class Foo {
+        new class {
             constructor(message) {
                 this.message = message;
             }
@@ -4864,9 +4864,26 @@ issue_2496: {
                     this.go();
                 });
             }
-        }
-        new Foo("FAIL").run();
+        }("FAIL").run();
     }
     expect_stdout: "PASS"
     node_version: ">=6"
 }
+
+issue_2416: {
+    options = {
+        keep_classnames: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        class Foo {}
+        console.log(Foo.name);
+    }
+    expect: {
+        console.log((class Foo {}).name);
+    }
+    expect_stdout: "Foo"
+    node_version: ">=6"
+}

test/mocha/spidermonkey.js

@@ -10,7 +10,7 @@ describe("spidermonkey export/import sanity test", function() {
         var command = uglifyjs + " --self -cm --wrap SpiderUglify -o spidermonkey | " +
             uglifyjs + " -p spidermonkey -cm";
 
-        exec(command, function(err, stdout) {
+        exec(command, { maxBuffer: 1048576 }, function(err, stdout) {
             if (err) throw err;
 
             eval(stdout);