[Chapel Merge] Disable '.offset()' for single-value-idxType range

Branch: refs/heads/master
Revision: e25dc4b
Author: bradcray
Log Message:

Merge pull request #17673 from bradcray/make-offset-illegal-for-single-idxType-ranges

Disable '.offset()' for single-value-idxType ranges

[reviewed by @lydia-duncan]

This makes the '.offset()' routine illegal for single-value-idxType
ranges, similar to what we've done for other operations like
.translate, .exterior, .expand, etc. When making those other
operations illegal, I was surprised that we didn't need to do the same
for .offset(), but with --baseline testing re-enabled, it turns out
that we should've, as it results in OOB-style errors.

Modified Files:
A test/types/range/enum/singleValEnum-errors-offset.good

M modules/internal/ChapelRange.chpl
M test/types/range/enum/singleValEnum-errors.chpl
M test/types/range/enum/singleValEnum-errors.compopts
M test/types/range/userAPI/rangeAPItest.chpl
M test/types/range/userAPI/singleEnumAPITest.good

Compare: https://github.com/chapel-lang/chapel/compare/65e356211369...e25dc4b6926d