Move most remaining service request code into its own module
This moves the emitBindJmp, emitBindJcc, and emitBindCall functions, as
well as some supporting players, into a new module
service-requests-x64.cpp. The two functions freeRequestStub and
getFreeStub are still in tx64, but I think that makes sense.
The way this structure is turning out still doesn't sit well with me,
but I can't quite pin down why. At least now all the nasty-looking
helpers for the emitBind* functions are behind a clean module boundary,
and the external interface (in service-requests-x64.h) is pretty clean.
Getting the new file compiling forced me to clean up some includes, and
move DataBlock up to the HPHP namespace (it was in Transl before).
Reviewed By: @jdelong
Differential Revision:
D957725