Revert "[SDK] Switch dds and dtd to use an AOT snapshot"

This reverts commit 6450d76f1f.

Reason for revert: Breaking Flutter G3 roll

Original change's description:
> [SDK] Switch dds and dtd to use an AOT snapshot
>
> TEST=ci
>
> Change-Id: Ib65ca1d1a05d3bc7b5f5cab25d90fc459ec8d853
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/387133
> Reviewed-by: Ben Konyi <bkonyi@google.com>
> Commit-Queue: Siva Annamalai <asiva@google.com>

Change-Id: I9985919063cacfc8673b3e2946eaa163e90c9cc3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/411200
Auto-Submit: Ben Konyi <bkonyi@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Siva Annamalai <asiva@google.com>

utils/dartdev/BUILD.gn

@@ -23,18 +23,10 @@ application_snapshot("generate_dartdev_snapshot") {
   main_dart = "../../pkg/dartdev/bin/dartdev.dart"
   training_args = [ "--help" ]
 
-  if (dart_target_arch != "ia32" && dart_target_arch != "x86") {
-    deps = [
-      "../..:runtime_precompiled",
-      "../dds:dds_aot",
-      "../dtd:dtd_aot",
-    ]
-  } else {
-    deps = [
-      "../dds:dds",
-      "../dtd:dtd",
-    ]
-  }
+  deps = [
+    "../dds:dds",
+    "../dtd:dtd",
+  ]
 
   vm_args = []
   output = "$root_gen_dir/dartdev.dart.snapshot"