src: don't use NewExternal() with unaligned strings

V8 3.20.9 enforces that external pointers are aligned on a two-byte
boundary.

We cannot portably guarantee that for the source code strings that
tools/js2c.py generates so simply stop using String::NewExternal()
altogether (and by extension String::ExternalAsciiStringResource).

Fixes the following run-time assert:

  FATAL ERROR: v8::String::NewExternal() Pointer is not aligned

node.gyp

@@ -101,7 +101,6 @@
         'src/node_os.cc',
         'src/node_script.cc',
         'src/node_stat_watcher.cc',
-        'src/node_string.cc',
         'src/node_watchdog.cc',
         'src/node_zlib.cc',
         'src/pipe_wrap.cc',
@@ -127,7 +126,6 @@
         'src/node_os.h',
         'src/node_root_certs.h',
         'src/node_script.h',
-        'src/node_string.h',
         'src/node_version.h',
         'src/node_watchdog.h',
         'src/node_wrap.h',

src/node.cc

@@ -72,7 +72,6 @@ typedef int mode_t;
 #include "node_constants.h"
 #include "node_javascript.h"
 #include "node_version.h"
-#include "node_string.h"
 #if HAVE_OPENSSL
 # include "node_crypto.h"
 #endif
@@ -2403,6 +2402,8 @@ static void SignalExit(int signal) {
 
 
 void Load(Handle<Object> process_l) {
+  HandleScope handle_scope(node_isolate);
+
   process_symbol = String::New("process");
   domain_symbol = String::New("domain");
 
@@ -2420,8 +2421,7 @@ void Load(Handle<Object> process_l) {
   // are not safe to ignore.
   try_catch.SetVerbose(false);
 
-  Local<Value> f_value = ExecuteString(MainSource(),
-                                       IMMUTABLE_STRING("node.js"));
+  Local<Value> f_value = ExecuteString(MainSource(), String::New("node.js"));
   if (try_catch.HasCaught())  {
     ReportException(try_catch);
     exit(10);

src/node_javascript.cc

@@ -22,7 +22,7 @@
 #include "v8.h"
 #include "node.h"
 #include "node_natives.h"
-#include "node_string.h"
+
 #include <string.h>
 #if !defined(_MSC_VER)
 #include <strings.h>
@@ -33,7 +33,7 @@ using namespace v8;
 namespace node {
 
 Handle<String> MainSource() {
-  return BUILTIN_ASCII_ARRAY(node_native, sizeof(node_native)-1);
+  return String::New(node_native, sizeof(node_native) - 1);
 }
 
 void DefineJavaScript(v8::Handle<v8::Object> target) {
@@ -42,7 +42,8 @@ void DefineJavaScript(v8::Handle<v8::Object> target) {
   for (int i = 0; natives[i].name; i++) {
     if (natives[i].source != node_native) {
       Local<String> name = String::New(natives[i].name);
-      Handle<String> source = BUILTIN_ASCII_ARRAY(natives[i].source, natives[i].source_len);
+      Handle<String> source = String::New(natives[i].source,
+                                          natives[i].source_len);
       target->Set(name, source);
     }
   }