Backport: add missing -inl.h
Backport: correct so we can build without JS_THREADSAFE
Backport: include ForkJoin-inl anyway that jsinterpinl is included
Backport: Correct alignment of simulated mainThread field in 32-bit debug builds
Backport: update dummy Runtime so that it aligns properly on opt arm builds
Remove ForkJoin-inl.h file