Fix non-release build crashes on Arm

[SeanTAllen]

The code removed in this commit dates to the very first Arm 32 support
that Sylvan added. It appears during the elapsed years, that the bug
that was being worked around was fixed. The workaround is now itself
a source of odd behavior and crashes for me as I try to get main
working on a Raspberry Pi 4 running a 32-bit version of Raspbian.

With the code as it stands before this patch is applied, I get
crashes when running the standard library tests in debug mode. I
can reliably reproduce using the serialise tests but it was
also happening "randomly" with other tests as well.

After removing Sylvan's workaround, I have seen a total lack of the
issue.

Closes #3851

[ponylang-main]

Hi @SeanTAllen,

The changelog - fixed label was added to this pull request; all PRs with a changelog label need to have release notes included as part of the PR. If you haven't added release notes already, please do.

Release notes are added by creating a uniquely named file in the .release-notes directory. We suggest you call the file 3860.md to match the number of this pull request.

The basic format of the release notes (using markdown) should be:

## Title

End user description of changes, why it's important,
problems it solves etc.

If a breaking change, make sure to include 1 or more
examples what code would look like prior to this change
and how to update it to work after this change.

Thanks.