Make sure CEE3ERP is invoked in LE 31-bit XPLINK (Zowe v2)

Proposed changes

When an ABEND occurs and there is a user-defined ESTAEX in an LE application, the language environment must be notified via a call to CEE3ERP; that way LE has a chance to handle things like hitting a stack guard page. If we don't call CEE3ERP, things can go terribly wrong.

At some point, the ZSS 31-bit build was changed to use XPLINK and the CEE3ERP call in the recovery facility was erroneously limited to non-XPLINK 31-bit LE environments.

This PR changes the code to call the CEE3ERP routine in XPLINK 31-bit LE applications.

This PR addresses issue:

Type of change

Please delete options that are not relevant.

[x] Bug fix (non-breaking change which fixes an issue)

PR Checklist

Please delete options that are not relevant.

[x] If the changes in this PR are meant for the next release / mainline, this PR targets the "staging" branch.
[x] My code follows the style guidelines of this project (see: Contributing guideline)
[x] I have commented my code, particularly in hard-to-understand areas
[x] New and existing unit tests pass locally with my changes
[x] Relevant update to CHANGELOG.md
[x] My changes generate no new warnings
[x] I have added tests that prove my fix is effective or that my feature works, or describe a test method below

Testing

Regression testing of ZSS/ the config manager is needed.

zowe / zowe-common-c