Now, jsDynamicCast has the same / similar mechanism to WebCore::jsDynamicDowncast to inject efficient casting. So, let's remove jsDynamicDowncast. And inject WebCore specializations into JSC::jsDynamicCast in WebCore side.
Created attachment 335301 [details] Patch
Created attachment 335310 [details] Patch
Comment on attachment 335310 [details] Patch r=me
Committed r229416: <https://trac.webkit.org/changeset/229416>
<rdar://problem/38268343>
*** Bug 172685 has been marked as a duplicate of this bug. ***