Port c-link-to-rust-va-list-fn to Rust

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -12,7 +12,6 @@ run-make/c-dynamic-dylib/Makefile
 run-make/c-dynamic-rlib/Makefile
 run-make/c-link-to-rust-dylib/Makefile
 run-make/c-link-to-rust-staticlib/Makefile
-run-make/c-link-to-rust-va-list-fn/Makefile
 run-make/c-static-dylib/Makefile
 run-make/c-static-rlib/Makefile
 run-make/c-unwind-abi-catch-lib-panic/Makefile

tests/run-make/c-link-to-rust-va-list-fn/rmake.rs

@@ -0,0 +1,21 @@
+// test.c and its static library checkrust.rs make use of variadic functions (VaList).
+// This test checks that the use of this feature does not 
+// prevent the creation of a functional binary.
+// See https://github.com/rust-lang/rust/pull/49878
+
+//@ ignore-cross-compile
+
+use run_make_support::{cc, extra_c_flags, run, rustc, static_lib};
+
+fn main() {
+    rustc()
+        .input("checkrust.rs")
+        .run();
+    cc()
+        .input("test.c")
+        .input(static_lib("checkrust"))
+        .out_exe("test")
+        .args(&extra_c_flags())
+        .run();
+    run("test");
+}