miri compiletest: no longer allow some warnings in rustc test suite

[RalfJung]

In pre-subtree days we had these -A to have the Miri toolstate break less often. But nowadays it just causes confusion when Miri CI works in rustc but fails on the Miri side so let's get rid of this difference.

r? @oli-obk

[rustbot]

The Miri subtree was changed

cc @rust-lang/miri

[rust-log-analyzer]

The job x86_64-gnu-tools failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

tests/pass/shims/time-with-isolation2.rs ... ok
tests/pass/0weak_memory_consistency.rs ... ok

tests/pass/shims/fs.rs FAILED:
command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/miri" "--error-format=json" "-Dwarnings" "-Dunused" "-Zui-testing" "--target" "x86_64-unknown-linux-gnu" "tests/pass/shims/fs.rs" "-Zmiri-disable-isolation" "--edition" "2021"




---
+++ <stderr output>
+error: unused import: `c_char`
+  --> $DIR/fs.rs:LL:CC
+   |
+LL | use std::ffi::{c_char, OsString};
+   |
+   |
+   = note: `-D unused-imports` implied by `-D unused`
+
+error: the item `c_char` is imported redundantly
+   |
+   |
+LL | use std::ffi::{c_char, OsString};
+   |                ------ the item `c_char` is already imported here
+...
+LL |     use std::ffi::{c_char, CStr, CString};
+
+
+error: miri cannot be run on programs that fail compilation
+error: aborting due to 3 previous errors
+
+



There were 1 unmatched diagnostics that occurred outside the testfile and had no pattern
    Error: miri cannot be run on programs that fail compilation
There were 1 unmatched diagnostics at tests/pass/shims/fs.rs:8
    Error: unused import: `c_char`

There were 1 unmatched diagnostics at tests/pass/shims/fs.rs:34
There were 1 unmatched diagnostics at tests/pass/shims/fs.rs:34
    Error: the item `c_char` is imported redundantly
full stderr:
error: unused import: `c_char`
  --> tests/pass/shims/fs.rs:8:16
   |
   |
LL | use std::ffi::{c_char, OsString};
   |
   |
   = note: `-D unused-imports` implied by `-D unused`

error: the item `c_char` is imported redundantly
   |
   |
LL | use std::ffi::{c_char, OsString};
   |                ------ the item `c_char` is already imported here
...
LL |     use std::ffi::{c_char, CStr, CString};


error: miri cannot be run on programs that fail compilation
error: aborting due to 3 previous errors




FAILURES:
    tests/pass/shims/fs.rs

test result: FAIL. 1 tests failed, 294 tests passed, 5 ignored, 0 filtered out
Error: 
   0: tests failed

Backtrace omitted. Run with RUST_BACKTRACE=1 environment variable to display it.
Run with RUST_BACKTRACE=full to include source snippets.

Caused by:
  process didn't exit successfully: `/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/deps/compiletest-694d1b8f129cddde --quiet` (exit status: 1)
Build completed unsuccessfully in 0:02:26

[RalfJung]

Ah I guess we need a rustc-push first...

[RalfJung]

Superseded by #112244