[Chapel Merge] Don't warn when `CHPL_TARGET_CPU` is set to the in

Branch: refs/heads/main
Revision: 7922efe
Author: ronawho
Link: Don't warn when `CHPL_TARGET_CPU` is set to the inferred value on Crays by ronawho · Pull Request #19341 · chapel-lang/chapel · GitHub
Log Message:

Merge pull request #19341 from ronawho/no-warn-same-cpu-prgenv

Don't warn when CHPL_TARGET_CPU is set to the inferred value on Crays

[reviewed by @mppf]

On Cray XC/EX CHPL_TARGET_CPU is based on the loaded craype- cpu
targeting module and we don't want users to set it explicitly so we warn
if they do. However, there's no reason to warn if the user set the value
to the inferred one so stop doing that here. This was causing test
failures for a prediff because we inject the chplenv into the prediff
env, which resulted in CHPL_TARGET_CPU being set explicitly, which
caused the printchplenv called from the prediff to warn. While here fix
a python2/3 incompatibly in the prediff.

Part of Cray/chapel-private#3147

Modified Files:
M test/compflags/link/sungeun/static_dynamic.prediff

M util/chplenv/chpl_cpu.py

Compare: https://github.com/chapel-lang/chapel/compare/48824fa1ae7e...7922efe62aa2