bolt: `libbolt_rt_hugify.a` & `libbolt_rt_instr.a` aren't generated on arm64

[sylvestre]

they are generated on amd64

[llvmbot]

@llvm/issue-subscribers-bolt

[rafaelauler]

Those libs are instrumentation support and runtime code to enable code huge pages for the application. They are not available for AArch64 (yet).