A64: Synchronize with r18084.

test/cctest/test-representation.cc

Index: test/cctest/test-representation.cc
diff --git a/test/cctest/test-representation.cc b/test/cctest/test-representation.cc
index 15321f3ce794e8534518f5d41ec5a25047506d82..95a65cbbf7b31d12826957946861c881549b1dac 100644
--- a/test/cctest/test-representation.cc
+++ b/test/cctest/test-representation.cc
@@ -121,4 +121,8 @@ TEST(RepresentationMoreGeneralThan) {
   TestPairNegative(Representation::HeapObject(), Representation::Integer32());
   TestPairPositive(Representation::Double(), Representation::Integer32());
   TestPairPositive(Representation::Tagged(), Representation::Integer32());
+
+  TestPairNegative(Representation::None(), Representation::External());
+  TestPairNegative(Representation::External(), Representation::External());
+  TestPairPositive(Representation::External(), Representation::None());
 }