The __even_in_range() intrinsic to the MSP430 C compiler does not have anything to do with the behavior of the edge sensitivity for the P2 I/O interrupt. This is mechanism documented in the MSP430 C Compiler User's Guide. It provides guidance to the C Compiler for optimization of switch statements processing in interrupt service routines.
The MSP430 implements a register (ie. P2IV) which provides an interrupt vector to help quickly identify the highest priority source for the P2 interrupt. For the non-TI microcontroller, you will need to modify the IntSpiGPIOHandler to address the hardware specifics of the microcontroller you are using.