My previous speculative ARM64_32 build fix in copyLCharsFromUCharSource() was wrong. I've now fixed it to use choose the default case instead of the ARM64 case if the target is ARM64_32. I also disabled more dynamicPoisoning code in ARM64_32. This code assumes a 64-bit pointer which is not applicable here.
<rdar://problem/37162310>
Created attachment 332982 [details] proposed patch.
Created attachment 332985 [details] patch for landing.
Thanks for the review. Landed in r228022: <http://trac.webkit.org/r228022>.