[release-branch.go1.16] runtime: simplify histogram buckets considerably
There was an off-by-one error in the time histogram buckets calculation
that caused the linear sub-buckets distances to be off by 2x.
The fix was trivial, but in writing tests I realized there was a much
simpler way to express the calculation for the histogram buckets, and
took the opportunity to do that here. The new bucket calculation also
fixes the bug.
For #50732.
Fixes #50733.
Change-Id: Idae89986de1c415ee4e148f778e0e101ca003ade
Reviewed-on: https://go-review.googlesource.com/c/go/+/380094
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
(cherry picked from commit
2e9dcb508647dc473a37ecfa244d2bc4a1843ab4)
Reviewed-on: https://go-review.googlesource.com/c/go/+/384620