Previously, we would normalize *all* of
- the absolute path to the repository checkout
- the /rustc/$sha for stage1 (if `remap-debuginfo` was enabled)
- the /rustc/$sha for download-rustc
- the sysroot for download-rustc

Now, we consistently only normalize /rustc/FAKE_PREFIX. Not only is this
much simpler, but it also avoids ongoing maintenance for download-rustc
and makes it much less likely that tests break by accident.

- Change `tests/ui/track-diagnostics/track6.rs` to use a relative path
  instead of an absolute one. I am not actually sure why `track_caller`
works here, but it does seem to work 🤷

- Pass `-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX` to all
  suites, not just UI. In particular, mir-opt tests emit /rustc/ paths
  in their output.

These tend to have special handling in a bunch of places anyway, so the variant helps remember that.  And I think it's easier to grok than non-Scalar Aggregates sometimes being `Immediates` (like I got wrong and caused 109992).  As a minor bonus, it means we don't need to generate poison LLVM values for them to pass around in `OperandValue::Immediate`s.

... by enabling xgot feature

Co-Authored-By: Zixing Liu <[email protected]>

So that bootstrap itself can be built with warnings not being treated as errors.

…ompiler-errors

Add a distinct `OperandValue::ZeroSized` variant for ZSTs

These tend to have special handling in a bunch of places anyway, so the variant helps remember that.  And I think it's easier to grok than `Aggregate`s sometimes being `Immediates` (after all, I previously got that wrong and caused rust-lang#109992).  As a minor bonus, it means we don't need to generate poison LLVM values for ZSTs to pass around in `OperandValue::Immediate`s.

Inspired by rust-lang#110021 (comment), so
r? ```@compiler-errors```

…-translatable, r=oli-obk,RalfJung

Use translatable diagnostics in `rustc_const_eval`

This PR:

* adds a `no_span` parameter to `note` / `help` attributes when using `Subdiagnostic` to allow adding notes/helps without using a span
* has minor tweaks and changes to error messages

…jackh726

Fix linkage for large binaries on mips64 platforms

This pull request fixes the linkage for large binaries on mips64 platforms by enabling the `xgot` feature in LLVM.

It is well understood that the generated binary will gain a hefty performance penalty where the external symbol jumps now cost at least three instructions each.

Also, this pull request does not address the same issue on the mips32 counterparts (due to being unable to test the changes thoroughly).

Should fix rust-lang#52108

Stop normalizing so many different prefixes

Previously, we would normalize *all* of
- the absolute path to the repository checkout
- the /rustc/$sha for stage1 (if `remap-debuginfo` was enabled)
- the /rustc/$sha for download-rustc
- the sysroot for download-rustc

Now, we consistently only normalize /rustc/FAKE_PREFIX. Not only is this much simpler, but it also avoids ongoing maintenance for download-rustc and makes it much less likely that tests break by accident.

- Change `tests/ui/track-diagnostics/track6.rs` to use a relative path instead of an absolute one. I am not actually sure why `track_caller` works here, but it does seem to work 🤷

- Pass `-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX` to all suites, not just UI. In particular, mir-opt tests emit /rustc/ paths in their output.

r? `@cjgillot` since you reviewed rust-lang#110699 - this is the test that it doesn't regress :)

Respect CARGOFLAGS in bootstrap.py

This makes it possible to pass flags to bootstrap itself, for consistency with std/rustc: https://github.com/rust-lang/rust/blob/04265621f9a82cfc2fc2278b935dcc5d4a1c39b7/src/bootstrap/builder.rs#L1446-L1447
Like RUSTFLAGS, this doesn't support CARGOFLAGS_BOOTSTRAP: https://github.com/rust-lang/rust/blob/6674dcda7a1da4c66e0aa0cfc67b27e42f4ebb34/src/bootstrap/bootstrap.py#L883-L884

I found this useful recently when I wanted to pass `-Zsparse-registry` to an old checkout of the compiler from before it was stabilized in cargo.

Add `--warnings warn` flag to `x.py`

So that bootstrap itself can be built with warnings not being treated as errors.

Fixes: rust-lang#76805

r? `@jyn514`