Revert "An async method's return annotation (if there is one) must be "Awaitable""

Summary: This reverts commit 519de5f5e46a591d1811d9e6913f675733e7cff3.
D1566028

Reviewed By: @markw65

Differential Revision: D1584349
Get Eval.JitGlobalTranslationLimit working again

Summary: It looks like this has been broken for a while. This diff gets this
option working again, changes things to leverage the shouldTranslate()
function instead of turning off Eval.Jit, and also counts prologue
translations.

Reviewed By: @alexmalyshev

Differential Revision: D1582259
Fix type error in framework perf script

Reviewed By: @fredemmott

Differential Revision: D1582554