cmd/cgo/internal/testsanitizers: skip some libfuzzer tests in short mode
These tests are newly-running now that we have installed a C++ toolchain
on the clang builders, but one of them doesn't actually complete in short
mode.
For #67698.
Change-Id: Id1ff4c05e380426d920277c13495f30e23561a4e
Reviewed-on: https://go-review.googlesource.com/c/go/+/589295
Auto-Submit: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>