gotools: copy some golang.org/x directories for cmd/go test

cmd/go now depends on a few vendored golang.org/x packages. We
need to copy them for running cmd/go test.

Change-Id: I64fc4cd427d8917223a354e85fb6e7378231aa90
Reviewed-on: https://go-review.googlesource.com/c/gollvm/+/216659
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/gotools/CMakeLists.txt b/gotools/CMakeLists.txt
index 946f6f0..cf70562 100644
--- a/gotools/CMakeLists.txt
+++ b/gotools/CMakeLists.txt
@@ -164,6 +164,9 @@
        "${cmd_srcroot}/go/internal:src/cmd/go"
        "${cmd_srcroot}/internal:src/cmd"
        "${cmd_srcroot}/go/testdata:src/cmd/go"
+       "${libgo_srcroot}/go/golang.org/x/mod:src/cmd/vendor/golang.org/x"
+       "${libgo_srcroot}/go/golang.org/x/crypto:src/cmd/vendor/golang.org/x"
+       "${libgo_srcroot}/go/golang.org/x/xerrors:src/cmd/vendor/golang.org/x"
     "COPYFILES"
        "${libgo_binroot}/zdefaultcc.go:src/cmd/go/internal/cfg/"
        "${libgo_binroot}/objabi.go:src/cmd/internal/objabi"