Add Uint32 representation

runtime/vm/flow_graph_allocator.cc

Index: runtime/vm/flow_graph_allocator.cc
diff --git a/runtime/vm/flow_graph_allocator.cc b/runtime/vm/flow_graph_allocator.cc
index 406e2d38f885eabc70b1f14d46bbb0076242024e..bb092dfc8c810bf52cb39c8c94129f9e5035f006 100644
--- a/runtime/vm/flow_graph_allocator.cc
+++ b/runtime/vm/flow_graph_allocator.cc
@@ -2753,6 +2753,9 @@ static Representation RepresentationForRange(Representation definition_rep) {
   if (definition_rep == kUnboxedMint) {
     // kUnboxedMint is split into two ranges, each of which are kUntagged.
     return kUntagged;
+  } else if (definition_rep == kUnboxedUint32) {
+    // kUnboxedUint32 is untagged.
+    return kUntagged;
   }
   return definition_rep;
 }