[BOLT-AArch64] Support large test binary

Summary:
Rewrite how data/code markers are interpreted, so the code
can have constant islands essentially anywhere. This is necessary to
accomodate custom AArch64 assembly code coming from mozjpeg. Allow
any function to refer to the constant island owned by any other
function. When this happens, we pull the constant island from the
referred function and emit it as our own, so it will live nearby
the code that refers to it, allowing us to freely reorder functions
and code pieces. Make bolt more strict about not changing anything
in non-simple ARM functions, as we need to preserve offsets for
those functions we don't interpret their jump tables (currently
any function with jump tables in ARM is non-simple and is left
untouched).

(cherry picked from FBD6402324)