Rollup merge of #144125 - GuillaumeGomez:new-annotations, r=Kobzol

Add new `ignore-backends` and `needs-backends` tests annotations

Part of https://github.com/rust-lang/compiler-team/issues/891.

Next step will be to add these annotations in the files where either the output is different based on the codegen (like `asm` tests) or that are known to fail in the GCC backend.

cc `@oli-obk` `@antoyo`
r? `@Kobzol`

src/bootstrap/src/core/build_steps/test.rs

@@ -1757,6 +1757,10 @@ NOTE: if you're sure you want to do this, please open an issue as to why. In the
         cmd.arg("--host").arg(&*compiler.host.triple);
         cmd.arg("--llvm-filecheck").arg(builder.llvm_filecheck(builder.config.host_target));
 
+        if let Some(codegen_backend) = builder.config.default_codegen_backend(compiler.host) {
+            cmd.arg("--codegen-backend").arg(&codegen_backend);
+        }
+
         if builder.build.config.llvm_enzyme {
             cmd.arg("--has-enzyme");
         }