[MCA] Add tests for IPC on Cortex-A55

The tests compare IPC statistics that MCA provides with IPC values
measured on Cortex-A55 hardware. For hardware tests, each snippet is
run in a loop unrolled by 1000, and IPC is measured by linux-perf.

Several tests do not match the hardware: the skewed ALU is not
supported, LDR seem to be missing a forwarding path.

Differential Revision: https://reviews.llvm.org/D98174