Fix switch table detection. Disassemble all instructions in non-simple functions.

Summary:
Switch table can contain __builtin_unreachable(). As a result,
a compiler may place an entry into a jump table that contains
an address immediately past the last instruction in the function.
Sometimes it may coincide with a start of the next function in
the binary. Thus when we check for switch tables in such cases
we have to check more than a single entry until we see either
an address inside containing function or some address outside
different from the address past the last instruction.

Additonally, don't stop disassembly after discovering that the
function was not simple. We need to detect all outside
references whenever possible.

(cherry picked from FBD3850825)