Use the test harness for the cranelift-tools::filetests test (#8373)

* Use libtest-mimic to make filetests behave like a normal test

* Skip using libtest-mimic

* Remove the explicit filetests test definition

cranelift/Cargo.toml

@@ -16,11 +16,6 @@ workspace = true
 name = "clif-util"
 path = "src/clif-util.rs"
 
-[[test]]
-name = "filetests"
-path = "tests/filetests.rs"
-harness = false
-
 [dependencies]
 cfg-if = { workspace = true }
 cranelift-codegen = { workspace = true, features = ["disas", "trace-log", "timing"] }

cranelift/tests/filetests.rs

@@ -1,4 +1,5 @@
-fn main() -> anyhow::Result<()> {
+#[test]
+fn filetests() -> anyhow::Result<()> {
     // Run all the filetests in the following directories.
     cranelift_filetests::run(false, false, &["filetests".into(), "docs".into()])?;
     Ok(())