[vm] Check prefix.loadLibrary is called and returns before prefix members are used.

Not loading is actually deferred.

Bug: https://github.com/dart-lang/sdk/issues/41974
Change-Id: I62688007bd36dbcb2e8ffb4a1fd2dceb1775b1c8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/149053
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>

https://dart.googlesource.com/sdk/+/f049a410e5de6fbf6745606cf59735047bfadf4a
diff --git a/commits.json b/commits.json
index 58a3143..8aedc6d 100644
--- a/commits.json
+++ b/commits.json
@@ -1,5 +1,5 @@
 {
   "external/github.com/flutter/engine":"c5d012900f7db0dc5dc9afb46f76d16b87915db0",
   "external/github.com/flutter/flutter":"e853155c7e36264514970dd6b67eb110fd394f78",
-  "sdk":"a56368926e9b2525c825db6f6e4dae288f9316fb"
+  "sdk":"f049a410e5de6fbf6745606cf59735047bfadf4a"
 }
\ No newline at end of file