[BOLT] Properly handle non-standard function refs

Summary:
Application code can reference functions in a non-standard way, e.g.
using arithmetic and bitmask operations on them. One example is if a
program checks if a function is below a certain address or within
a certain address range to perform a low-level optimization or generate
a proper code (JIT).

Instead of relying on a relocation value (symbol+addend), we use only
the symbol value, and then check if the value is inside the function.
If it is, we treat it as a code reference against location within the
function, otherwise we handle it as a non-standard function reference
and issue a warning.

(cherry picked from FBD7996274)