Bootstrap update

[cuviper]

• Replace version placeholders with 1.95.0
• Bump stage0 to 1.95.0-beta.1
• Clear STAGE0_MISSING_TARGETS
• Update cfg(bootstrap)
• Reformat with the new stage0

[rustbot]

Some changes occurred in compiler/rustc_attr_parsing

cc @jdonszelmann, @JonathanBrouwer

The Miri subtree was changed

cc @rust-lang/miri

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

Some changes occurred to the CTFE machinery

cc @RalfJung, @oli-obk, @lcnr

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

stdarch is developed in its own repository. If possible, consider making this change to rust-lang/stdarch instead.

cc @Amanieu, @folkertdev, @sayantn

The run-make-support library was changed

cc @jieyouxu

This PR changes rustc_public

cc @oli-obk, @celinval, @ouz-a, @makai410

[rustbot]

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[Zalathar]

Reminder to myself that after the bootstrap bump has merged, we can remove the re-export of rustc_data_structures::assert_matches! and just import from the standard library again, resolving #151359.