Fix several issues with ES6 redeclaration checks

test/mjsunit/harmony/block-let-declaration.js

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 38 matching lines @@
 
 if (true) {
   let y;
   assertEquals(undefined, y);
 }
 
 // Invalid declarations are early errors in harmony mode and thus should trigger
 // an exception in eval code during parsing, before even compiling or executing
 // the code. Thus the generated function is not called here.
 function TestLocalThrows(str, expect) {
-  assertThrows("(function(){ 'use strict'; " + str + "})", expect);
+  assertThrows("(function(arg){ 'use strict'; " + str + "})", expect);
 }
 
 function TestLocalDoesNotThrow(str) {
-  assertDoesNotThrow("(function(){ 'use strict'; " + str + "})()");
+  assertDoesNotThrow("(function(arg){ 'use strict'; " + str + "})()");
 }
 
 // Test let declarations in statement positions.
 TestLocalThrows("if (true) let x;", SyntaxError);
 TestLocalThrows("if (true) {} else let x;", SyntaxError);
 TestLocalThrows("do let x; while (false)", SyntaxError);
 TestLocalThrows("while (false) let x;", SyntaxError);
 TestLocalThrows("label: let x;", SyntaxError);
 TestLocalThrows("for (;false;) let x;", SyntaxError);
 TestLocalThrows("switch (true) { case true: let x; }", SyntaxError);
@@ skipping 27 matching lines @@
 // Test var declarations in statement positions.
 TestLocalDoesNotThrow("if (true) var x;");
 TestLocalDoesNotThrow("if (true) {} else var x;");
 TestLocalDoesNotThrow("do var x; while (false)");
 TestLocalDoesNotThrow("while (false) var x;");
 TestLocalDoesNotThrow("label: var x;");
 TestLocalDoesNotThrow("for (;false;) var x;");
 TestLocalDoesNotThrow("switch (true) { case true: var x; }");
 TestLocalDoesNotThrow("switch (true) { default: var x; }");
 
+// Test that redeclarations of functions are only allowed in outermost scope.
+TestLocalThrows("{ let f; var f; }");
+TestLocalThrows("{ var f; let f; }");
+TestLocalThrows("{ function f() {} let f; }");
+TestLocalThrows("{ let f; function f() {} }");
+TestLocalThrows("{ function f() {} var f; }");
+TestLocalThrows("{ var f; function f() {} }");
+TestLocalThrows("{ function f() {} function f() {} }");
+TestLocalThrows("function f() {} let f;");
+TestLocalThrows("let f; function f() {}");
+TestLocalDoesNotThrow("function arg() {}");
+TestLocalDoesNotThrow("function f() {} var f;");
+TestLocalDoesNotThrow("var f; function f() {}");
+TestLocalDoesNotThrow("function f() {} function f() {}");
+
+function g(f) {
+  function f() { return 1 }
+  return f()
+}
+assertEquals(1, g(function() { return 2 }))
+
+
 // Test function declarations in source element and
 // sloppy statement positions.
 function f() {
   // Sloppy source element positions.
   function g0() {
     "use strict";
     // Strict source element positions.
     function h() { }
     {
       function h1() { }
     }
   }
   {
     function g1() { }
   }
 }
 f();
 
 // Test function declarations in statement position in strict mode.
 TestLocalThrows("function f() { if (true) function g() {}", SyntaxError);
 TestLocalThrows("function f() { if (true) {} else function g() {}", SyntaxError);
 TestLocalThrows("function f() { do function g() {} while (false)", SyntaxError);
 TestLocalThrows("function f() { while (false) function g() {}", SyntaxError);
 TestLocalThrows("function f() { label: function g() {}", SyntaxError);
 TestLocalThrows("function f() { for (;false;) function g() {}", SyntaxError);
 TestLocalThrows("function f() { switch (true) { case true: function g() {} }", SyntaxError);
 TestLocalThrows("function f() { switch (true) { default: function g() {} }", SyntaxError);