[Math] implement Math.random as TFJ builtin.

src/factory.cc

 // Copyright 2014 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.
 
 #include "src/factory.h"
 
 #include "src/accessors.h"
 #include "src/allocation-site-scopes.h"
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
@@ skipping 762 matching lines @@
 }
 
 
 Handle<Context> Factory::NewNativeContext() {
   Handle<FixedArray> array =
       NewFixedArray(Context::NATIVE_CONTEXT_SLOTS, TENURED);
   array->set_map_no_write_barrier(*native_context_map());
   Handle<Context> context = Handle<Context>::cast(array);
   context->set_native_context(*context);
   context->set_errors_thrown(Smi::kZero);
+  context->set_math_random_index(Smi::kZero);
   Handle<WeakCell> weak_cell = NewWeakCell(context);
   context->set_self_weak_cell(*weak_cell);
   DCHECK(context->IsNativeContext());
   return context;
 }
 
 
 Handle<Context> Factory::NewScriptContext(Handle<JSFunction> function,
                                           Handle<ScopeInfo> scope_info) {
   DCHECK_EQ(scope_info->scope_type(), SCRIPT_SCOPE);
@@ skipping 1811 matching lines @@
     Handle<AccessorInfo> prototype =
         Accessors::FunctionPrototypeInfo(isolate(), attribs);
     AccessorConstantDescriptor d(Handle<Name>(Name::cast(prototype->name())),
                                  prototype, attribs);
     map->AppendDescriptor(&d);
   }
 }
 
 }  // namespace internal
 }  // namespace v8