Importing rustc-1.71.0

Bug: 288268986
Test: ./build.py --lto=thin
Change-Id: Idffe995937cee91f5b480ce61ef8267475cec993
diff --git a/vendor/serde_json-1.0.91/tests/ui/parse_key.rs b/vendor/serde_json-1.0.91/tests/ui/parse_key.rs
new file mode 100644
index 0000000..858bd71
--- /dev/null
+++ b/vendor/serde_json-1.0.91/tests/ui/parse_key.rs
@@ -0,0 +1,5 @@
+use serde_json::json;
+
+fn main() {
+    json!({ "".s : true });
+}