batcheval: add range tombstone support for DeleteRange

[erikgrinaker]

This patch adds the parameter UseExperimentalRangeTombstone for
DeleteRange, which deletes the span using an MVCC range tombstone.
The new version gate MVCCRangeTombstones must be checked before using
it. storage.ExperimentalMVCCDeleteRangeUsingTombstone() is added to
carry out the actual deletion.

This is a bare-bones implementation to allow writing range keys via the
KV API for testing and development purposes. It has significant
shortcomings, and will be fleshed out at a later time.

Touches #70415.
Replaces #76203.

Release note: None

[cockroach-teamcity]

This change is 

[aliher1911]

Is GH description correct regarding which commits belong to this PR? It looks only the last one is relevant.

Some nits as I think I already went through this code before.

[erikgrinaker]

Is GH description correct regarding which commits belong to this PR? It looks only the last one is relevant.

Ah, it's because I rebased the base branch mvcc-range-tombstones onto master, so the old commits that are no longer in the base branch are then considered part of this branch instead. It'll be resolved once I rebase all of the PRs to the new base branch. Updated the PR description to be agnostic to the number of prior commits.

[nicktrav]

Reviewed 20 of 20 files at r4, all commit messages.
Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @aliher1911 and @erikgrinaker)

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pkg/storage/testdata/mvcc_histories/range_tombstone_mutations, line 1 at r4 (raw file):

# Set up some point keys, point/range tombstones, and intents.

nit: diagram would be useful here.

[erikgrinaker]

@aliher1911 May want to take a quick look at this again, since there's been a few changes to range keys since it was initially submitted -- nothing major though.

[aliher1911]

I gave it another read and it looks good.

There's something wrong with the request itself though. I can see latest version with all updates in "Files changed", but neither VS-Code view, nor Reviewable shows it. Both show diff with some older commit which rolls back changes from master massively.

[erikgrinaker]

I gave it another read and it looks good.

Thanks!

There's something wrong with the request itself though. I can see latest version with all updates in "Files changed", but neither VS-Code view, nor Reviewable shows it. Both show diff with some older commit which rolls back changes from master massively.

Are you sure you're using the correct base though? Remember, this used to be onto the mvcc-range-tombstones feature branch, but is now rebased onto master. May be that your local VSCode checkout and/or Reviewable gets that wrong and pulls in a bunch of stuff from the old base branch?

Using "Show full diff" in Reviewable shows the correct changes, as does comparing the branch to master in VSCode, so idk.

[erikgrinaker]

TFTR!

bors r=aliher1911

[craig]

Build succeeded:

• GitHub CI (Cockroach)