Well this is embarrassing...
I started with a hello world example for the KL17. __disable_interrupt fails at linking telling me
Error[Li005]: no definition for "__iar_builtin_disable_interrupt"
and asm ("CPSID f") fails to compile, telling me
Error[Og006]: Error in inline assembly: "Illegal sequence of interrupt flags"
It looks like you need to include "intrinsics.h" starting with IAR 8.22 but I have another project for the K24 and both of these methods work without including intrinsics.h. Including it with my KL17 projects doesn't fix it.