Migrate run-make/rustdoc-target-spec-json-path to rmake

Author: GuillaumeGomez

tests/run-make/rustdoc-target-spec-json-path/Makefile

@@ -0,0 +1,15 @@
+// Test that rustdoc will properly canonicalize the target spec json path just like rustc.
+
+use run_make_support::{rustc, rustdoc, tmp_dir};
+
+fn main() {
+    let out_dir = tmp_dir().join("rustdoc-target-spec-json-path");
+    rustc().crate_type("lib").input("dummy_core.rs").target("target.json").run();
+    rustdoc()
+        .input("my_crate.rs")
+        .output(out_dir)
+        .arg("-L")
+        .arg(tmp_dir())
+        .target("target.json")
+        .run();
+}