Merge pull request #18731 from bradcray/user-error-bad-import-2
Change internal error to user error for bad import expression
[reviewed by @dlongnecke-cray]
This resolves an error pointed out by @cassella in which an import
statement with an unexpected expression caused an internal error
rather than a helpful user-facing one. Changed to a user error and
added Paul's test to prevent backsliding.
Modified Files: A test/statements/errors/importIllegalExpr.chpl