[Chapel Merge] refactor isNothingvalue proc

Branch: refs/heads/master
Revision: 3d4e32e
Author: mppf
Log Message:

Merge pull request #17470 from 12mohaned/isNothingvalue

refactor isNothingvalue proc

[PR by @12mohaned - thanks! reviewed/tested/merged by @mppf]

Resolves #17254.

This a simpler version of a previous PR
This PR adds isNothing accepting a type or a value to Types.chpl.

Modified Files:
A test/library/standard/Types/isNothing-proc.chpl

A test/library/standard/Types/isNothing-proc.good
M modules/standard/Types.chpl

Compare: https://github.com/chapel-lang/chapel/compare/77853cadc525...3d4e32e97e9f