cmd/vendor: eliminate vet-lite

cmd/vet, now simplified to a single function call is now authoritative,
not a copy of vet-lite.

The update-xtools.sh script now uses the imports of cmd/vet as the
roots for vendoring.

Change-Id: I4faef3fcf3db10b3a3930726e8d0720a3c8395da
Reviewed-on: https://go-review.googlesource.com/c/150297
Run-TryBot: Alan Donovan <[email protected]>
Reviewed-by: Daniel Martí <[email protected]>

Author: adonovan

src/cmd/vendor/golang.org/x/tools/go/analysis/cmd/vet-lite/main.go

@@ -1,7 +1,7 @@
 #!/bin/sh
 #
 # update-xtools.sh: idempotently update the vendored
-# copy of the x/tools repository used by vet-lite.
+# copy of the x/tools repository used by cmd/vet.
 
 set -u
 
@@ -11,7 +11,11 @@ xtools=$(dirname $(dirname $analysis))
 
 vendor=$(dirname $0)
 
-go list -f '{{.ImportPath}} {{.Dir}}' -deps golang.org/x/tools/go/analysis/cmd/vet-lite |
+# Find the x/tools packages directly imported by cmd/vet.
+go list -f '{{range $k, $v := .ImportMap}}{{$k}} {{end}}' cmd/vet |
+  grep golang.org/x/tools |
+  # Vendor their transitive closure of dependencies.
+  xargs go list -f '{{.ImportPath}} {{.Dir}}' -deps |
   grep golang.org/x/tools |
   while read path dir
   do
@@ -23,5 +27,5 @@ go list -f '{{.ImportPath}} {{.Dir}}' -deps golang.org/x/tools/go/analysis/cmd/v
 
 echo "Copied $xtools@$(cd $analysis && git rev-parse --short HEAD) to $vendor" >&2
 
-go build -o /dev/null ./golang.org/x/tools/go/analysis/cmd/vet-lite ||
-  { echo "Failed to build vet-lite"; exit 1; } >&2
+go build -o /dev/null cmd/vet ||
+  { echo "Failed to build cmd/vet"; exit 1; } >&2