[dart2wasm] Update interop specializers to live in library with specialized member.

Change-Id: I072240ff98bb9f571156a101b8cf18dcc8c6877c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/439480
Reviewed-by: Srujan Gaddam <srujzs@google.com>
Reviewed-by: Ömer Ağacan <omersa@google.com>
Commit-Queue: Nate Biggs <natebiggs@google.com>

https://dart.googlesource.com/sdk/+/b207705bd58feb40af536ad82beecedf6a32e523

DEPS

diff --git a/DEPS b/DEPS
index 0ff5d35..4aa353d 100644
--- a/DEPS
+++ b/DEPS
@@ -229,7 +229,7 @@
 ]
 
 deps = {
-  'flutter/engine/src/flutter/third_party/dart': Var('dart_git') + '/sdk' + '@' + '83d862217e5960cc1e8055312f950d29d7803f7e',
+  'flutter/engine/src/flutter/third_party/dart': Var('dart_git') + '/sdk' + '@' + 'b207705bd58feb40af536ad82beecedf6a32e523',
 
   'flutter': Var('flutter_git') + '/mirrors/flutter' + '@' + '43657f3baa17bc1df6cc15da8b0fea2290c2c4fd',
 

commits.json

diff --git a/commits.json b/commits.json
index 51cf7dd..a9c8539 100644
--- a/commits.json
+++ b/commits.json
@@ -1,4 +1,4 @@
 {
   "flutter":"43657f3baa17bc1df6cc15da8b0fea2290c2c4fd",
-  "flutter/engine/src/flutter/third_party/dart":"83d862217e5960cc1e8055312f950d29d7803f7e"
+  "flutter/engine/src/flutter/third_party/dart":"b207705bd58feb40af536ad82beecedf6a32e523"
 }
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