runtime: create setGCPercent method for gcControllerState
This change breaks out the computations done by setGCPercent into
a method on gcControllerState for easier testing later. It leaves behind
the global implementation details.
For #44167.
Change-Id: I3b0cf1475b032fcd4ebbd01cf4e80de0b55ce7b0
Reviewed-on: https://go-review.googlesource.com/c/go/+/306602
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com>