[BOLT] Fix jump table placement for non-simple functions

Summary:
When we move a jump table to either hot or cold new section
(-jump-tables=move), we rely on a number of taken branches from the table
to decide if it's hot or cold. However, if the function is non-simple, we
always get 0 count, and always move the table to the cold section.
Instead, we should make a conservative decision based on the execution
count of the function.

(cherry picked from FBD7058127)