The slow-path of CheckedInt32Mod(x,y) when x is found to be negative
still had the power of two right hand side optimization, and thus would
perform a dynamic check on y. Now the same dynamic check was done for
the fast-path, and the word operations for this check were pure, leading
to weird bit materialization in TurboFan (due to sea of nodes). But
there's not really a point to be clever for the slow-path, so we just
insert the Uint32Mod operation directly here, which completely avoids
the problem.

This improves the Kraken/audio-oscillator test from around 73ms to 69ms.

Bug: v8:8069
Change-Id: Ie8ea667136c95df2bd8c5ba56ebbc6bd2442ff23
Reviewed-on: https://chromium-review.googlesource.com/c/1259063Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56370}