Revert "internal/trace: change Less to make sorting events deterministice"
Revert "internal/trace: change Less to make sorting events deterministice"

This reverts commit 1764609b8b245323210eab39c4b586291d3a45a5.

Reason for revert: It breaks the dragonfly trybot, in which there are sometimes (non-deterministically) Events with the same timestamp that have to occur in a specific order.

Change-Id: I714e640c6ab5ccb23d5577e8aa98c7716ede7ad2
Reviewed-on: https://go-review.googlesource.com/114356
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

golang/go,CAFxX/go,CAFxX/go,josharian/go,nawawi/go,josharian/go,cloudflare/go,CAFxX/go,cloudflare/go,golang/go,golang/go,josharian/go,josharian/go,akutz/go,golang/go,akutz/go,akutz/go,nawawi/go,cloudflare/go,cloudflare/go,nawawi/go,CAFxX/go,golang/go,josharian/go,CAFxX/go,josharian/go,nawawi/go,nawawi/go,golang/go,akutz/go,nawawi/go,cloudflare/go,josharian/go,cloudflare/go,CAFxX/go,golang/go,cloudflare/go,akutz/go,nawawi/go,akutz/go,nawawi/go,cloudflare/go,akutz/go,akutz/go,CAFxX/go,josharian/go,CAFxX/go,golang/go