tree a39cf71a044cf9cd8588009157c637ce9e41313c
parent 70f7c802582130861844026e1c1cc5ab5f922c24
author Guillaume Maudoux <guillaume.maudoux@tweag.io> 1699286655 -0800
committer Copybara-Service <copybara-worker@google.com> 1699286712 -0800

Change `--extra_toolchains` precedence to last-wins, instead of first-wins.

This only changes the precedence within all uses of `--extra_toolchains`, it does not change the precedence for `register_toolchains` calls.

After this, the priority order for toolchains is:
1. Consider toolchains registered via `--extra_toolchains`
  1. Within this set, the last mentioned toolchain has highest priority
2. Consider toolchains registered via `register_toolchains`
  1. Within this set, the first mentioned toolchain has highest priority

In all cases, pseudo-targets like `:all` and `/...` are ordered by Bazel's package loading mechanism, which is currently using a lexicographic ordering.

Fixes #19945.

Closes #19942. Closes #20031.

PiperOrigin-RevId: 579845262
Change-Id: Ibd9c32e5479a6a27717734852b875f9b3f31b510