[test]: Add some test cases for for-loops

Bug: tint:952
Change-Id: I156e29a74ce3942a39f25dc5bfb3d5467e206fce
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/57201
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: James Price <jrprice@google.com>
diff --git a/test/statements/for/scoping.wgsl.expected.hlsl b/test/statements/for/scoping.wgsl.expected.hlsl
new file mode 100644
index 0000000..459eb43
--- /dev/null
+++ b/test/statements/for/scoping.wgsl.expected.hlsl
@@ -0,0 +1,13 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+void f() {
+  {
+    int must_not_collide = 0;
+    while (true) {
+    }
+  }
+  int must_not_collide = 0;
+}