[vm] Rename *MintOp to *Int64Op to emphasis that they operate on unboxed values.

runtime/vm/flow_graph_range_analysis.h

Index: runtime/vm/flow_graph_range_analysis.h
diff --git a/runtime/vm/flow_graph_range_analysis.h b/runtime/vm/flow_graph_range_analysis.h
index 09778a072e9f8150289fe6b4e5f7606d6d11d346..197078db1d67cc611db8664cc98c7bca3c8cb62d 100644
--- a/runtime/vm/flow_graph_range_analysis.h
+++ b/runtime/vm/flow_graph_range_analysis.h
@@ -584,9 +584,9 @@ class RangeAnalysis : public ValueObject {
   // Value that are known to be smi or mint.
   GrowableArray<Definition*> values_;
 
-  GrowableArray<BinaryMintOpInstr*> binary_mint_ops_;
+  GrowableArray<BinaryInt64OpInstr*> binary_int64_ops_;
 
-  GrowableArray<ShiftMintOpInstr*> shift_mint_ops_;
+  GrowableArray<ShiftInt64OpInstr*> shift_int64_ops_;
 
   // All CheckArrayBound instructions.
   GrowableArray<CheckArrayBoundInstr*> bounds_checks_;