globset: add more tests for single-asterisk pattern
globset: add more tests for single-asterisk pattern

This adds a few tests that check for bugs reported here:
https://github.com/rust-lang/cargo/issues/4268

The bugs reported in the aforementioned issue are probably caused by not
enabling the `literal_separator` option in `GlobBuilder`. Enabling that
in the tests under question fixes the issue.

Closes #773

BurntSushi/ripgrep,BurntSushi/ripgrep,BurntSushi/ripgrep,BurntSushi/ripgrep