Align compiletests with immediate-abort panic strategy

Author: LegNeato

tests/compiletests/src/main.rs

@@ -403,7 +403,7 @@ fn rust_flags(codegen_backend_path: &Path, target_arch: &str) -> String {
         "-Cdebuginfo=2",
         "-Cembed-bitcode=no",
         &format!("-Ctarget-feature=+{target_arch}"),
-        "-Cpanic=abort",
+        "-Cpanic=immediate-abort",
         "-Cno-redzone=yes",
         &format!("-Cllvm-args=-arch={target_arch}"),
         "-Cllvm-args=--override-libm",

tests/compiletests/ui/lang/compile_fail.stderr

@@ -1,4 +1,4 @@
-error[E0433]: failed to resolve: use of unresolved module or unlinked crate `std`
+error[E0433]: cannot find module or crate `std` in this scope
   --> $DIR/compile_fail.rs:5:14
    |
 LL |     let _s = std::fs::File::create("foo.txt");