[Chapel Merge] Minor improvements to `greptests`

Branch: refs/heads/main
Revision: 51cc8a7
Author: vasslitvinov
Link: Minor improvements to `greptests` by vasslitvinov · Pull Request #18884 · chapel-lang/chapel · GitHub
Log Message:

Merge pull request #18884 from vasslitvinov/improve-greptests

Minor improvements to greptests

This is a followup to #17546:

  • rename the option -help to --help as more conventional
  • allow passing multiple options to grep
  • minor code restructuring to improve readability

A potential usability improvement is to switch the file-type argument style
from -t tests / -t futures etc. to --tests / --futures etc.

r: @lydia-duncan

Modified Files:
M util/devel/greptests

Compare: https://github.com/chapel-lang/chapel/compare/f20de0922fac...51cc8a7976db