TestLoadImportsC just works on Go 1.10. And there's no good reason
that TestLoadAllSyntaxImportErrors shouldn't work, even though
it's currently always skipped.
Change-Id: Icd8d311f12c5731cc635937a00251eab0a3077ec
Reviewed-on: https://go-review.googlesource.com/139117
Reviewed-by: Alan Donovan <adonovan@google.com>