objc-runtime-x is an extension of objc-runtime based on Apple's objc4-237.
It is authored by Paul Guyot.

It currently adds the following two functions:

objc_methodCallv
objc_methodCallv_stret

It is written in assembly language, directly derived from objc_msgSendv and
objc_msgSendv_stret.

These functions work like objc_msgSendv and objc_msgSendv_stret except that they
take a pointer to the function to call as a parameter. This pointer is used
instead of objc_msgSend. In other words, they basically allow one to call an
Objective-C function, within Apple runtime, with a marg_list.
