The arm64 css jit could use a deallocated argument register to swap the argument registers in, which would generate invalid code. To prevent this, let's use a designated temporary register for now because we have a plentiful supply of registers, then we can do better register organization later.
Created attachment 232273 [details]
Comment on attachment 232273 [details]
View in context: https://bugs.webkit.org/attachment.cgi?id=232273&action=review
> + RELEASE_ASSERT(minimumRegisterCountForAttributes <= registerCount);
Please make this an assertion instead of a release assert.
In this case, we do not risk a security problem if the assert is false. RegisterAllocator ensure we crash if we ever overallocate.