The assembly in sys/mips/include/profile.h will only work for o32 ABI.
I initially turned _mcount into a stub that calls abort() in
https://github.com/CTSRD-CHERI/cheribsd/commit/0f800913c4fcc08125b870e7.
However, jhb@ suggestedthat not building profiling on MIPS64 is the better solution.
I currently have 11912 .po files in my build directory so disabling profile support
should also noticeably speed up the build.
Obtained from: CheriBSD (https://github.com/CTSRD-CHERI/cheribsd/commit/cfa27e6a3d697b59f0fb8215f824c3fc976fbf5e)