refactor(metrics): move to core

[AaronO]

Avoids overhead of wrapping ops (extra alloc due to reboxing futures for async ops) also stabilizes Deno.metrics().ops.

I'll deprecate byte fields (legacy of previous buffer-based op-layer) in a follow-up PR

[bartlomieju]

Nice to see 100 lines removed. How's the performance?

[bartlomieju]

Can you stabilize typing for Deno.OpMetrics in this PR as well?

[AaronO]

Nice to see 100 lines removed. How's the performance?

Before (main):

date_now:            	n = 500000, dt = 0.032s, r = 15625000/s, t = 64ns/op
op_void_sync:        	n = 10000000, dt = 0.980s, r = 10204082/s, t = 98ns/op
op_void_async:       	n = 1000000, dt = 0.369s, r = 2710027/s, t = 369ns/op
perf_now:            	n = 500000, dt = 0.087s, r = 5747126/s, t = 174ns/op
url_parse:           	n = 50000, dt = 0.086s, r = 581395/s, t = 1719ns/op

After (#12386):

date_now:            	n = 500000, dt = 0.031s, r = 16129032/s, t = 62ns/op
op_void_sync:        	n = 10000000, dt = 0.715s, r = 13986014/s, t = 71ns/op
op_void_async:       	n = 1000000, dt = 0.283s, r = 3533569/s, t = 283ns/op
perf_now:            	n = 500000, dt = 0.076s, r = 6578947/s, t = 151ns/op
url_parse:           	n = 50000, dt = 0.083s, r = 602410/s, t = 1660ns/op

[bartlomieju]

The type declarations are still not updated for OpMetrics (ie. they are still in lib.deno.unstable.d.ts)

[AaronO]

The type declarations are still not updated for OpMetrics (ie. they are still in lib.deno.unstable.d.ts)

Should we stabilize them after stripping the byte fields (and other changes I would like to make) or stabilize .ops now and keep the breaking changes for 2.0 ?

[bartlomieju]

The type declarations are still not updated for OpMetrics (ie. they are still in lib.deno.unstable.d.ts)

Should we stabilize them after stripping the byte fields (and other changes I would like to make) or stabilize .ops now and keep the breaking changes for 2.0 ?

I'm fine with both approaches as there aren't many known consumers of this API. Your call.

[AaronO]

The type declarations are still not updated for OpMetrics (ie. they are still in lib.deno.unstable.d.ts)

Should we stabilize them after stripping the byte fields (and other changes I would like to make) or stabilize .ops now and keep the breaking changes for 2.0 ?

I'm fine with both approaches as there aren't many known consumers of this API. Your call.

Lets stabilize as is and break in follow-up changes, we can break for 2.0 since the changes would mostly be cleanups instead of imperative improvements