stdlib: This commit added warning for exit default behavior

This commit imported the warn from m5.util library and added a function
 named "defaultBehaviorWarning" to the exit_event_generators.py file
under src/python/gem5/simulator.

This function takes two string variable and output a warning that
contains a warning about the default behavior, the behavior type,
 and an detail explaination about it.

Jira Issue: https://gem5.atlassian.net/browse/GEM5-1235

Change-Id: I54500425eaa1a556769aa1f8ea6b32852694c94d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/61189
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
1 file changed