allow pointer math using CPointer repr

This means that NativeCall's OpaquePointer type can be gistified as
OpaquePointer<0x7f9e8db8fda0>, which will be helpful for debugging
when making bindings to C libraries. This also allows us to do basic
pointer arithmethic so that we can iterate over the bytes of a CStr
by incrementing the memory address.
fix typo in CArray.elems error message
[nativecall.c] add a cast to get rid of a warning
Fix merging of inline table entries.

Need to add offsets to return address deopt location, locals, and
lexicals.
Improve deopt debug fprintfs.
Merge remote-tracking branch 'origin/master' into moar-jit

Conflicts:
	src/spesh/deopt.c

Was commented-out debugging sections