Auto merge of #128073 - jieyouxu:exp-print-target-list, r=<try>

[EXPERIMENTAL] try to see how to make `print-target-list` pass

Experiments for #127877.

r? `@ghost`

try-job: x86_64-gnu-llvm-18

Author: bors

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -26,7 +26,6 @@ run-make/pdb-buildinfo-cl-cmd/Makefile
 run-make/pgo-gen-lto/Makefile
 run-make/pgo-indirect-call-promotion/Makefile
 run-make/print-calling-conventions/Makefile
-run-make/print-target-list/Makefile
 run-make/raw-dylib-alt-calling-convention/Makefile
 run-make/raw-dylib-c/Makefile
 run-make/redundant-libs/Makefile

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

@@ -0,0 +1,10 @@
+//! Check that all targets returned by `--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.lines() {
+        bare_rustc().target(target).print("sysroot").run();
+    }
+}