[vm/ffi] Re-land "[vm/ffi] FFI callbacks on X64."

There are minor fixes for dartkb and windows.
The original revision is in patchset 1.

Change-Id: I9ab6e5fdb33fb4e84ea520c283fe94323616a8ce
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/103129
Commit-Queue: Samir Jindel <sjindel@google.com>
Auto-Submit: Samir Jindel <sjindel@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>

https://dart.googlesource.com/sdk/+/225a30163700d03111079cf63e2c1cda455f8d9b
diff --git a/commits.json b/commits.json
index cf7b130..2b6706c 100644
--- a/commits.json
+++ b/commits.json
@@ -1,5 +1,5 @@
 {
   "external/github.com/flutter/engine":"ee6a9c40492e54a0ae160293900d9e3b42b725d7",
   "external/github.com/flutter/flutter":"1bd85dd6c207d69c148b92ec8f68244c00dec503",
-  "sdk":"edadc9c88149b52bb090dd2cc12de4e3fafb7640"
+  "sdk":"225a30163700d03111079cf63e2c1cda455f8d9b"
 }
\ No newline at end of file