[ dartfuzz ] Initial refactor of Dartfuzz

- Started cleaning up places where we emit matching parens/braces manually
- Started handling indentation in less places
- Started de-duping code
- Started using constants where possible

Output code is still logically and structurally the same, although it formats
differently.

Change-Id: I367c8629174139c7083f6a12b7221230d884e628
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/120742
Reviewed-by: Aart Bik <ajcbik@google.com>
Commit-Queue: Ben Konyi <bkonyi@google.com>

https://dart.googlesource.com/sdk/+/85093bed12f9f8a68856e312e1d69c24ed4c19ad
diff --git a/commits.json b/commits.json
index d56f919..7be4fde 100644
--- a/commits.json
+++ b/commits.json
@@ -1,5 +1,5 @@
 {
   "external/github.com/flutter/engine":"e3b5d8ef32266326d5de3f43f8ceab46095ee72e",
   "external/github.com/flutter/flutter":"dee75839087fb9cdfab342dd26587caa51b31eaf",
-  "sdk":"892fcf2c4586bc00a23c19ddfd8be0064681ad05"
+  "sdk":"85093bed12f9f8a68856e312e1d69c24ed4c19ad"
 }
\ No newline at end of file