Execute JS for the first time in Rust rewrite.

Implements code_fetch handler in Rust.

Add ability to embed string assets (for typescript declaration files)

Remove deno_cc and deno_cc_nosnapshot targets.

src/internal.h

@@ -18,6 +18,9 @@ struct deno_s {
   deno_recv_cb cb;
   void* data;
 };
+// TODO(ry) Remove these when we call deno_reply_start from Rust.
+char** deno_argv();
+int deno_argc();
 }
 
 namespace deno {