These source files fail to build with 'go test ./...'.
Move them into testdata so that only test.bash will see them.

Updates #30228

Change-Id: I3673f3cb64b0c128a2bca5fee7679b672fe90770
Reviewed-on: https://go-review.googlesource.com/c/163212Reviewed-by: Ian Lance Taylor <iant@golang.org>