Auto merge of #140233 - Zalathar:revert-new-executor, r=jieyouxu

Revert compiletest new-executor, to re-land without download-rustc

Revert <rust-lang/rust#139998> because the original merge triggered download-rustc, which messes with test metrics and prevents us from properly comparing them before/after the change.

The plan is to re-land this PR as-is, combined with a trivial compiler change to avoid download-rustc and get proper test metrics for comparison.

This reverts commit be181dd, reversing changes made to 645d0ad.

r? ghost

Author: bors