undo CL 166380043 / 0b54a0927656

This was a mistake; the cmd/api tool
depends on an old version of go/types.

««« original CL description
cmd/api: bump go.tools golden CL hash

TBR=bradfitz
R=rsc
CC=golang-codereviews
https://golang.org/cl/166380043
»»»

TBR=bradfitz, rsc
R=bradfitz, rsc
CC=golang-codereviews
https://golang.org/cl/167430043

src/cmd/api/run.go

@@ -27,7 +27,7 @@ import (
 // goToolsVersion is the hg revision of the go.tools subrepo we need
 // to build cmd/api.  This only needs to be updated whenever a go/types
 // bug fix is needed by the cmd/api tool.
-const goToolsVersion = "ae08a5291439"
+const goToolsVersion = "6698ca2900e2"
 
 var goroot string