rewrite invalid-so to rmake

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -55,7 +55,6 @@ run-make/incr-foreign-head-span/Makefile
 run-make/interdependent-c-libraries/Makefile
 run-make/intrinsic-unreachable/Makefile
 run-make/invalid-library/Makefile
-run-make/invalid-so/Makefile
 run-make/issue-107094/Makefile
 run-make/issue-109934-lto-debuginfo/Makefile
 run-make/issue-14698/Makefile

tests/run-make/invalid-so/Makefile

@@ -1,7 +0,0 @@
-include ../tools.mk
-
-DYLIB_NAME := $(shell echo | $(RUSTC) --crate-name foo --crate-type dylib --print file-names -)
-
-all:
-	echo >> $(TMPDIR)/$(DYLIB_NAME)
-	$(RUSTC) --crate-type lib --extern foo=$(TMPDIR)/$(DYLIB_NAME) bar.rs 2>&1 | $(CGREP) 'invalid metadata files for crate `foo`'

tests/run-make/invalid-so/rmake.rs

@@ -0,0 +1,17 @@
+// When a fake library was given to the compiler, it would
+// result in an obscure and unhelpful error message. This test
+// creates a false "foo" dylib, and checks that the standard error
+// explains that the file exists, but that its metadata is incorrect.
+// See https://github.com/rust-lang/rust/pull/88368
+
+use run_make_support::{dynamic_lib_name, fs_wrapper, rustc};
+
+fn main() {
+    fs_wrapper::create_file(dynamic_lib_name("foo"));
+    rustc()
+        .crate_type("lib")
+        .extern_("foo", dynamic_lib_name("foo"))
+        .input("bar.rs")
+        .run_fail()
+        .assert_stderr_contains("invalid metadata files for crate `foo`");
+}