Attempts to fix CFI state after reordering

Summary:
This patch introduces logic to check how the CFI instructions define a
table to help during stack unwinding at exception run time and attempts to fix
any problem in this table that may have been introduced by reordering the basic
blocks. If it fails to fix this problem, the function is marked as not simple
and not eligible for rewriting.

(cherry picked from FBD2633696)