runtime: use frame pointer unwind to get backtrace in goroutine profile

[zdyj3170101136]

Proposal Details

now, the goroutine profile use gopcinfotab to get backtrace.

if we use frame pointer, it would reduce lots of cost.

[randall77]

Closing as dup of #16638

[zdyj3170101136]

以#16638的重复结束

not a same question.

for now, the tracer use fp trace back.
but the goroutine profile do not use it.

[randall77]

Ok, then I don't think I understand exactly what you are proposing. Could you be more explicit?

[ianlancetaylor]

I don't see any API change here, so I don't think this needs to be a proposal. Taking it out of the proposal process.