KPTI + Retpoline Linux Benchmarking On Older Clarksfield / Penryn ThinkPads

The Go build test saw its performance drop by a few percent with KPTI + Retpoline while the Golang JSON parsing and garbage collection tests were less affected on these Lenovo ThinkPad computers.

GraphicsMagick as another largely CPU-bound test didn't see a statistically significant change in performance.

Compiling the Apache web server was about 5% slower on the older ThinkPads while just shy of 2% slower on the X1 Broadwell laptop.

While the kernel compilation test came in at under 4% slower on the older laptops.