Migrate `run-make/inline-always-many-cgu` to `rmake.rs`

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -61,7 +61,6 @@ run-make/glibc-staticlib-args/Makefile
 run-make/include_bytes_deps/Makefile
 run-make/incr-add-rust-src-component/Makefile
 run-make/incr-foreign-head-span/Makefile
-run-make/inline-always-many-cgu/Makefile
 run-make/interdependent-c-libraries/Makefile
 run-make/intrinsic-unreachable/Makefile
 run-make/invalid-library/Makefile

tests/run-make/inline-always-many-cgu/Makefile

@@ -1,8 +0,0 @@
-include ../tools.mk
-
-all:
-	$(RUSTC) foo.rs --emit llvm-ir -C codegen-units=2
-	if cat $(TMPDIR)/*.ll | $(CGREP) -e '\bcall\b'; then \
-		echo "found call instruction when one wasn't expected"; \
-		exit 1; \
-	fi

tests/run-make/inline-always-many-cgu/rmake.rs

@@ -0,0 +1,18 @@
+use run_make_support::fs_wrapper::read_to_string;
+use run_make_support::regex::Regex;
+use run_make_support::{read_dir, rustc};
+
+use std::ffi::OsStr;
+
+fn main() {
+    rustc().input("foo.rs").emit("llvm-ir").codegen_units(2).run();
+    let re = Regex::new(r"\bcall\b").unwrap();
+    let mut nb_ll = 0;
+    read_dir(".", |path| {
+        if path.is_file() && path.extension().is_some_and(|ext| ext == OsStr::new("ll")) {
+            assert!(!re.is_match(&read_to_string(path)));
+            nb_ll += 1;
+        }
+    });
+    assert!(nb_ll > 0);
+}