Sloppy mode webcompat: allow conflicting function declarations in blocks

test/mjsunit/regress/regress-4693.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Flags: --harmony-sloppy-function
+
+// In sloppy mode we allow function redeclarations within blocks for webcompat.
+(function() {
+  assertEquals(undefined, f);  // Annex B
+  if (true) {
+    assertEquals(2, f());
+    function f() { return 1 }
+    assertEquals(2, f());
+    function f() { return 2 }
+    assertEquals(2, f());
+  }
+  assertEquals(2, f());  // Annex B
+})();
+
+// Should still fail in strict mode
+assertThrows(`
+  (function() {
+    "use strict";
+    if (true) {
+      function f() { return 1 }
+      function f() { return 2 }
+    }
+  })();
+`, SyntaxError);