codec: 0doc.go: cleanup and add TODO to remove deprecated APIs used by old codecgen'ed files

codec/0doc.go

@@ -238,8 +238,15 @@ MID-STACK INLINING:
     do echo ; grep -E "cannot inline \(\*${i}\)." $TMPDIR/a7.txt; done 
 
   - When mid-stack inlining is enabled, consider doing the following:
-    - if 41<=inlineExtraCallCost<=56, make (buf)ioEncWriter.{writen1,writen2,writestr,writeb,atEndOfEncode} go:noinline
-    - if <=40, do nothing (no go:inline)
+    - if 41<=inlineExtraCallCost<=56,
+      make (buf)ioEncWriter.{writen1,writen2,writestr,writeb,atEndOfEncode} go:noinline
+    - if <=40,
+      do nothing (no go:inline)
+
+TODO:
+  - remove Deprecated APIs,
+    especially those only used by files generated by old versions of codecgen.
+    this is ok, as we have updated the GenVersion, ensuring that old ones break anyway.
 
 PUNTED:
   - To make Handle comparable, make extHandle in BasicHandle a non-embedded pointer,
@@ -266,5 +273,5 @@ BEFORE EACH RELEASE:
     Check this out by running: ./run.sh -z
     - look at those tagged ****, meaning they are not occupying full cache lines
     - look at those tagged <<<<, meaning they are larger than 32 words (something to watch)
-  - Run "golint -min_confidence 0.81"
+    - Run "golint -min_confidence 0.81"
 */