Revert "[vm] Defer object pools." and

       "[vm] Defer object pool entries in instructions bare mode."

This reverts commit 0bf8d38 and
             commit 63d17b0.

Reason for revert : Performance regression, please see flutter/flutter#73794

TEST=(none it is a revert).

Change-Id: I828734f00c55d5095f632b154d7f4ab27a184baf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/181542
Commit-Queue: Siva Annamalai <[email protected]>
Reviewed-by: Ryan Macnak <[email protected]>
Reviewed-by: Siva Annamalai <[email protected]>

Author: a-siva