Option to output precompiled instructions as a blob for use with mmap instead of assembly for use i…

runtime/bin/dartutils.cc

Index: runtime/bin/dartutils.cc
diff --git a/runtime/bin/dartutils.cc b/runtime/bin/dartutils.cc
index 396b116fdd6d6dadb4b3fff83cba50a42d8796e2..e180479bccbdf498047d151f1e11bbde78345d7f 100644
--- a/runtime/bin/dartutils.cc
+++ b/runtime/bin/dartutils.cc
@@ -180,6 +180,17 @@ bool DartUtils::IsDartBuiltinLibURL(const char* url_name) {
 }
 
 
+void* DartUtils::MapExecutable(const char* name, intptr_t* len) {
+  File* file = File::Open(name, File::kRead);
+  if (file == NULL) {
+    return NULL;
+  }
+  void* addr = file->MapExecutable(len);
+  file->Release();
+  return addr;
+}
+
+
 void* DartUtils::OpenFile(const char* name, bool write) {
   File* file = File::Open(name, write ? File::kWriteTruncate : File::kRead);
   return reinterpret_cast<void*>(file);