Fix trivial comment typos.

Fix type error in benchmark.h

Benchmark: Define benchmark_util_t in a separate file to avoid circular dependency

Refactor includes so trace point support builds

benchmark.h requires a definition of KS_LOG_PPTR, but its previous
placement in machine.h resulted in a circular include. This commit
factors out KS_LOG_PPTR and related definitions to a separate header,
creates the corresponding header for x86, and prevents circular
includes in the x86 builds

Benchmark: Pack arch-independent benchmark-related files into separate directories