[R] Zero-copy Arrow to R where possible

[asfimport]

In a few cases, such as int32 and float64, where there are no nulls (or nulls allowed, if ARROW-8348/ARROW-3263 happen), we should be able to ingest data from Arrow to R with zero copy. But from my reading of the source, we always allocate memory, and even in the simple cases, we always transform the data.

cc @romainfrancois @fsaintjacques

Reporter: Neal Richardson / @nealrichardson
Assignee: Romain Francois / @romainfrancois

Related issues:

• [R] Refactor R <-> Array conversion (is related to)

PRs and other links:

• GitHub Pull Request #10445

_{Note: This issue was originally created as ARROW-9140. Please see the migration documentation for further details.}

[asfimport]

Francois Saint-Jacques / @fsaintjacques:
That's already mentioned in ARROW-7798, maybe we can slice it in sub-tasks to limit the scope.

[asfimport]

Neal Richardson / @nealrichardson:
Issue resolved by pull request 10445
#10445