[JSC] Use AssemblyHelpers' type checking functions as much as possible
Created attachment 340584 [details] Patch
Created attachment 340587 [details] Patch
Created attachment 340588 [details] Patch
Comment on attachment 340588 [details] Patch rs=me
Committed r231905: <https://trac.webkit.org/changeset/231905>
<rdar://problem/40332977>