(cherry picked from commit 9148660)

This reverts commit 8a568d9.

(cherry picked from commit 764e3e2)

(cherry picked from commit 3f08997)

(cherry picked from commit 988f28d)

(cherry picked from commit 4c6d793)

(cherry picked from commit 7d80617)

There is a chance that these tools are being installed from an external LLVM
and we have no control over them. If any of these tools use symlinks, they will
fail during tarball distribution. This change makes copying process to resolve
symlinks just before placing them into the destination path.

Signed-off-by: onur-ozkan <[email protected]>
(cherry picked from commit cde58dd)

(cherry picked from commit ebbcfd4)

(cherry picked from commit 94bf8f0)

(cherry picked from commit 0910173)

…tions with dummy spans instead of dropping them entirely

Revert most of #133194 (except the test and the comment fixes). Then refix
not emitting locations at all when the correct location discriminator value
exceeds LLVM's capacity.

(cherry picked from commit 45ef927)

Previously, bootstrap was using `Config::last_modified_commit` unconditionally to figure
the commit has to download precompiled rustc artifact from CI, which was leading builds to
fail on tarball sources as `Config::last_modified_commit` requires `git` to be present in the project
source. This change makes bootstrap to call `Config::last_modified_commit` only when it's running on
git-managed source and read `git-commit-hash` file otherwise.

Signed-off-by: onur-ozkan <[email protected]>
(cherry picked from commit 903cddb)

[stable] Prepare Rust 1.84.1 point release

- [Fix ICE 132920 in duplicate-crate diagnostics.](#133304)
- [Fix errors for overlapping impls in incremental rebuilds.](#133828)
- [Fix slow compilation related to the next-generation trait solver.](#135618)
- [Fix debuginfo when LLVM's location discriminator value limit is exceeded.](#135643)
- Fixes for building Rust from source:
  - [Only try to distribute `llvm-objcopy` if llvm tools are enabled.](#134240)
  - [Add Profile Override for Non-Git Sources.](#135433)
  - [Resolve symlinks of LLVM tool binaries before copying them.](#135585)
  - [Make it possible to use ci-rustc on tarball sources.](#135722)

cc `@rust-lang/release`
r? ghost