runtime/trace: update outdated Task and Region documentation
A previous iteration of the tracer's user annotation API had different
names for tasks and regions, and used to return functions for ending
them rather than types with End methods. This CL updates the doc
comments to reflect those changes, and also fixes up the internal
documentation of the events (similar to go.dev/cl/465335, the stack
argument was in the wrong place in the list).
The User Log event internal documentation might also look wrong since
the value argument follows the stack argument. However, the User Log
event is a special case where the log message is appended immediately
following the normal event, including the stack argument. There isn't
much room to clarify this next to the event type definitions, so this CL
clarifies the comment where the event is encoded.
Change-Id: I846c709f6026ef01c0a272557d6390b2c17074e0
Reviewed-on: https://go-review.googlesource.com/c/go/+/472955 Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Carlos Amedee <carlos@golang.org>
Auto-Submit: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Nick Ripley <nick.ripley@datadoghq.com>