Migrate print-target-list to rmake

Author: Rejyr

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -89,7 +89,6 @@ run-make/pgo-gen-lto/Makefile
 run-make/pgo-gen-no-imp-symbols/Makefile
 run-make/pgo-indirect-call-promotion/Makefile
 run-make/pointer-auth-link-with-c/Makefile
-run-make/print-target-list/Makefile
 run-make/raw-dylib-alt-calling-convention/Makefile
 run-make/raw-dylib-c/Makefile
 run-make/raw-dylib-import-name-type/Makefile

tests/run-make/print-target-list/Makefile

@@ -0,0 +1,12 @@
+// Checks that all the targets returned by `rustc --print target-list` are valid
+// target specifications
+
+use run_make_support::bare_rustc;
+
+fn main() {
+    let targets = bare_rustc().print("target-list").run().stdout_utf8();
+
+    for target in targets.split_whitespace() {
+        bare_rustc().target(target).print("sysroot").run();
+    }
+}