Rollup merge of rust-lang#127041 - GuillaumeGomez:run-make-override-aliased-flags, r=Kobzol

Migrate `run-make/override-aliased-flags` to `rmake.rs`

Part of rust-lang#121876.

I voluntarily didn't use the helper methods to make it obvious what's tested.

r? ``@jieyouxu``

Author: GuillaumeGomez

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -117,7 +117,6 @@ run-make/obey-crate-type-flag/Makefile
 run-make/optimization-remarks-dir-pgo/Makefile
 run-make/optimization-remarks-dir/Makefile
 run-make/output-type-permutations/Makefile
-run-make/override-aliased-flags/Makefile
 run-make/overwrite-input/Makefile
 run-make/panic-abort-eh_frame/Makefile
 run-make/pass-linker-flags-flavor/Makefile

tests/run-make/override-aliased-flags/Makefile

@@ -0,0 +1,24 @@
+//@ ignore-cross-compile
+
+use run_make_support::rustc;
+
+// FIXME: it would be good to check that it's actually the rightmost flags
+// that are used when multiple flags are specified, but I can't think of a
+// reliable way to check this.
+fn main() {
+    // Test that `-O` and `-C opt-level` can be specified multiple times.
+    // The rightmost flag will be used over any previous flags.
+    rustc().arg("-O").arg("-O").input("main.rs").run();
+    rustc().arg("-O").arg("-C").arg("opt-level=0").input("main.rs").run();
+    rustc().arg("-C").arg("opt-level=0").arg("-O").input("main.rs").run();
+    rustc().arg("-C").arg("opt-level=0").arg("-C").arg("opt-level=2").input("main.rs").run();
+    rustc().arg("-C").arg("opt-level=2").arg("-C").arg("opt-level=0").input("main.rs").run();
+
+    // Test that `-g` and `-C debuginfo` can be specified multiple times.
+    // The rightmost flag will be used over any previous flags.
+    rustc().arg("-g").arg("-g").input("main.rs").run();
+    rustc().arg("-g").arg("-C").arg("debuginfo=0").input("main.rs").run();
+    rustc().arg("-C").arg("debuginfo=0").arg("-g").input("main.rs").run();
+    rustc().arg("-C").arg("debuginfo=0").arg("-C").arg("debuginfo=2").input("main.rs").run();
+    rustc().arg("-C").arg("debuginfo=2").arg("-C").arg("debuginfo=0").input("main.rs").run();
+}