Automated hardware architecture detection in procsmpl.cpp (feature request)

[PaulDapolito]

The performance event hardware counter codes used in src/procsmpl.cpp are specific to the Sandy Bridge generation of Intel processors. This results in an error being printed when examples/api_test is run (in addition to the performance event data being presumably lost) on a Westmere machine:

$ ./examples/api_test
perf_event_open: Invalid argument
perf_event_open: Invalid argument
perf_event_open: Invalid argument
perf_event_open: Invalid argument
perf_event_open: Invalid argument
perf_event_open: Invalid argument
perf_event_open: Invalid argument
perf_event_open: Invalid argument
perf_event_open: Invalid argument
perf_event_open: Invalid argument
perf_event_open: Invalid argument
0

These hardware counter encodings can be found on any architecture using a tool like perfmon2. Automated hardware architecture detection is desired in Mitos in order to allow it to be used out-of-the-box on architectures other than Sandy Bridge.