Revert "When tailcalling is not supported, loop over stages."

This reverts commit 945923e2145794c25de313c3d9d9acb2b676f2f2.

Reason for revert: performance impacts different than expected

Original change's description:
> When tailcalling is not supported, loop over stages.
>
> When [[clang::musttail]] is unavailable, using tailcalls seems to be
> less efficient on Android and Windows than using a conversion loop.
> This CL should bring our non-tailcalling platform performance back
> to previous levels.
>
> Change-Id: I90589d0550f5a9261e946541d19c8d7f633bc29c
> Bug: chromium:1504816
> Bug: chromium:1504823
> Reviewed-on: https://skia-review.googlesource.com/c/skcms/+/786459
> Commit-Queue: John Stiles <johnstiles@google.com>
> Auto-Submit: John Stiles <johnstiles@google.com>
> Reviewed-by: Brian Osman <brianosman@google.com>

Bug: chromium:1504816
Bug: chromium:1504823
Change-Id: I15a51bba3452e8bb067975e1ddc07db6a7a35528
Reviewed-on: https://skia-review.googlesource.com/c/skcms/+/787307
Commit-Queue: John Stiles <johnstiles@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
3 files changed