rewrite mingw-export-call-convention to rmake

Author: Oneirical

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -110,7 +110,6 @@ run-make/manual-link/Makefile
 run-make/many-crates-but-no-match/Makefile
 run-make/metadata-dep-info/Makefile
 run-make/min-global-align/Makefile
-run-make/mingw-export-call-convention/Makefile
 run-make/missing-crate-dependency/Makefile
 run-make/mixing-libs/Makefile
 run-make/msvc-opt-minsize/Makefile

tests/run-make/mingw-export-call-convention/Makefile

@@ -0,0 +1,13 @@
+// On windows-gnu, symbol exporting used to fail to export names
+// with no_mangle. #72049 brought this feature up to par with msvc,
+// and this test checks that the symbol "bar" is successfully exported.
+// See https://github.com/rust-lang/rust/issues/50176
+
+//@ only-x86_64-pc-windows-gnu
+
+use run_make_support::{llvm_readobj, rustc};
+
+fn main() {
+    rustc().input("foo.rs").run();
+    llvm_readobj().arg("--all").input("libfoo.dll.a").run().assert_stdout_contains("bar");
+}

tests/run-make/mingw-export-call-convention/rmake.rs

@@ -5,7 +5,9 @@
 // checks that no full file paths are exposed and that the override flag is respected.
 // See https://github.com/rust-lang/rust/pull/121297
 
-//@ only-windows
+//@ only-x86_64-pc-windows-msvc
+
+use run_make_support::{bin_name, invalid_utf8_contains, invalid_utf8_not_contains, run, rustc};
 
 fn main() {
     // Test that we don't have the full path to the PDB file in the binary