cargo-miri: better error message when RUSTC is not set
Currently, when running `cargo-miri` instead of `cargo miri` you get a very confusing.
```
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: NotPresent', src/tools/miri/cargo-miri/src/main.rs:83:41
```
error. This replaces that with a message telling them to use `cargo miri`
Make simd_shuffle_indices use valtrees
This removes the second-to-last user of the `destructure_mir_constant` query. So in a follow-up we can remove the query and just move the query provider function directly into pretty printing (which is the last user).
cc `@rust-lang/clippy` there's a small functional change, but I think it is correct?
compiletest: Only trim the end of process output
As of #94196, compiletest automatically trims process stderr/stdout output before printing it, to make failure info more compact.
This causes the first line of `run-coverage` output to be displayed incorrectly, because it uses leading whitespace to align line numbers.
Trimming only the end of the output string should still have the intended effect (e.g. removing trailing newlines), without causing problems for output that deliberately uses leading whitespace on the first line.
## Before
```
--- stdout -------------------------------
1| 1|fn main() { //
2| 1| let num = 9;
3| 1| while num >= 10 {
4| 0| }
5| 1|}
------------------------------------------
stderr: none
```
## After
```
--- stdout -------------------------------
1| 1|fn main() { //
2| 1| let num = 9;
3| 1| while num >= 10 {
4| 0| }
5| 1|}
------------------------------------------
stderr: none
```
Convert `run-make/coverage-reports` tests to use a custom compiletest mode
I was frustrated by the fact that most of the coverage tests are glued together with makefiles and shell scripts, so I tried my hand at converting most of them over to a newly-implemented `run-coverage` mode/suite in compiletest.
This ~~*mostly*~~ resolves#85009, ~~though I've left a small number of the existing tests as-is because they would require more work to fix/support~~.
---
I had time to go back and add support for the more troublesome tests that I had initially skipped over, so this PR now manages to completely get rid of `run-make/coverage-reports`.
---
The patches are arranged as follows:
- Declare the new mode/suite in bootstrap
- Small changes to compiletest that will be used by the new mode
- Implement the new mode in compiletest
- Migrate most of the tests over
- Add more code to bootstrap and compiletest to support the remaining tests
- Migrate the remaining tests (with some temporary hacks to avoid re-blessing them)
- Remove the temporary hacks and re-bless the migrated tests
- Remove the unused remnants of `run-make/coverage-reports`
Try running a sync automatically
absolutely no clue if this works, but it happens after the zulip message, so worst case we'll see the failure after the cron job did everything it currently does.
