[Chapel Merge] Add an error for when SysCTypes.chpl is missing

Branch: refs/heads/master
Revision: 043e6a4
Author: bradcray
Log Message:

Merge pull request #16699 from bradcray/error-for-missing-sysctypes

Add an error for when SysCTypes.chpl is missing

[reviewed by @gbtitus]

Greg hit an error that I’ve hit before where a missing SysCTypes.chpl file results in a series of errors that doesn’t make it particularly clear what the root problem is. This is a simple tweak that complains about the missing file rather than its effects.

Modified Files:
M compiler/parser/parser.cpp

Compare: https://github.com/chapel-lang/chapel/compare/3de7e0c68dbd...043e6a43fb8f