sql: move AsOfSystemTime to EvalContext

[otan]

Previously, AsOfSystemTime was on the SemaCtx. With the bounded
staleness work needing this in the EvalContext, and all other contexts
accessing this variable have access to EvalContext, move
AsOfSystemTime from SemaContext to EvalContext.

Release note: None

[cockroach-teamcity]

This change is 

[rytaft]

I think this was a good idea! I canceled bors-ing my other PR so feel free to re-open this.

[otan]

feel free to bors this if you accept @rytaft :D im off to bed!

[rytaft]

Reviewed 8 of 8 files at r1.
Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @otan)

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pkg/sql/conn_executor.go, line 2408 at r2 (raw file):

	p.semaCtx.SearchPath = ex.sessionData.SearchPath
	p.semaCtx.IntervalStyleEnabled = ex.sessionData.IntervalStyleEnabled
	p.semaCtx.AsOfSystemTime = nil

if you're not going to reset it here, seems like you should actually remove it from the SemaContext, no? I think there are still some references to this field. For example:

cockroach/pkg/sql/create_stats.go

Line 516 in 2eb1635

p.SemaCtx().AsOfSystemTime = &tree.AsOfSystemTime{Timestamp: *details.AsOf}

[otan]

revert also included

Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @rytaft)

---

pkg/sql/conn_executor.go, line 2408 at r2 (raw file):

Previously, rytaft (Rebecca Taft) wrote…

if you're not going to reset it here, seems like you should actually remove it from the SemaContext, no? I think there are still some references to this field. For example:

cockroach/pkg/sql/create_stats.go

Line 516 in 2eb1635

p.SemaCtx().AsOfSystemTime = &tree.AsOfSystemTime{Timestamp: *details.AsOf}

urgh, knew it was too good to be true to pass first go
removed!

[rytaft]

Thanks!!

Reviewed 5 of 5 files at r3, 10 of 10 files at r4.
Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @otan)

[otan]

bors r=rytaft

cheers

[craig]

Build succeeded:

• GitHub CI (Cockroach)