[Chapel Merge] Fix `CHPL_COMM_USE_(G|LL)DB` on mac

Branch: refs/heads/main
Revision: 51e6cb4
Author: ronawho
Link: Unavailable
Log Message:

Merge pull request #20108 from ronawho/portable-which

Fix CHPL_COMM_USE_(G|LL)DB on mac

[reviewed by @benharsh]

In 8aca2b3b575 we added a find_executable helper, which changed a
which call to /usr/bin/which --skip-alias --skip-functions. These
options ended up not being portable to the which command on mac, which
meant features like CHPL_COMM_USE_LLDB couldn't find executables they
needed and weren't working as a result. To fix this just go back to
using a plain which. The motivation for using the skip options was:

In case the user has an alias or shell function with different
behavior. I think we want to be using "classic which" rather than
anything derivative.

But I don't think this gave us trouble in the past.

Part of Cray/chapel-private#3374

Modified Files:
M runtime/src/chpl-launcher-common.c

Compare: https://github.com/chapel-lang/chapel/compare/e8b1c2b51c1e...51e6cb4f73fb