Fix more Windows compile errors

sky/engine/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("config.gni")
 if (is_clang) {
   import("//build/config/clang/clang.gni")
 }
 if (is_posix) {
   import("//build/config/gcc/gcc_version.gni")
@@ skipping 22 matching lines @@
   include_dirs = [
     ".",
     "$root_gen_dir/sky",
   ]
 
   cflags = []
   defines = []
 
   if (is_win) {
     cflags += [
+      "/wd4065",  # Switch statement contains 'default' but no 'case' labels.
+                  # In generated parser code.
       "/wd4305",  # Truncation from 'type1' to 'type2'.
       "/wd4324",  # Struct padded due to declspec(align).
+      "/wd4702",  # Unreachable code, happens in bison-generated code.
       "/wd4714",  # Function marked forceinline not inlined.
       "/wd4800",  # Value forced to bool.
       "/wd4996",  # Deprecated function call.
     ]
   }
 
   if (is_win) {
     if (component_mode == "shared_library") {
       defines += [ "USING_V8_SHARED" ]
     }
@@ skipping 26 matching lines @@
 
 # The follow configs apply to all targets except for unit tests, which rely on
 # static initializers.
 config("non_test_config") {
   cflags = []
 
   if (is_clang) {
     cflags += [ "-Wglobal-constructors" ]
   }
 }