When cleaning up the code for the register allocator, I negated a
helper function for readability but forgot to also negate its
implementation. For obvious reasons, that was not a good idea.

Change-Id: I0e5f4fbf5c83cce8b4891e0a84ef099df15d1ab0
Reviewed-on: https://chromium-review.googlesource.com/c/1445973Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Stephan Herhut <herhut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59206}