Revert of Remove ExternalArray, derived types, and element kinds

src/mips64/lithium-mips64.h

Index: src/mips64/lithium-mips64.h
diff --git a/src/mips64/lithium-mips64.h b/src/mips64/lithium-mips64.h
index 9a8681f069604523bb9340da400de9ca07e852f0..24088699d2a68436be29e6b3a59be85152c8201e 100644
--- a/src/mips64/lithium-mips64.h
+++ b/src/mips64/lithium-mips64.h
@@ -1672,8 +1672,14 @@
   ElementsKind elements_kind() const {
     return hydrogen()->elements_kind();
   }
+  bool is_external() const {
+    return hydrogen()->is_external();
+  }
   bool is_fixed_typed_array() const {
     return hydrogen()->is_fixed_typed_array();
+  }
+  bool is_typed_elements() const {
+    return is_external() || is_fixed_typed_array();
   }
 
   DECLARE_CONCRETE_INSTRUCTION(LoadKeyed, "load-keyed")
@@ -2258,8 +2264,12 @@
     inputs_[2] = value;
   }
 
+  bool is_external() const { return hydrogen()->is_external(); }
   bool is_fixed_typed_array() const {
     return hydrogen()->is_fixed_typed_array();
+  }
+  bool is_typed_elements() const {
+    return is_external() || is_fixed_typed_array();
   }
   LOperand* elements() { return inputs_[0]; }
   LOperand* key() { return inputs_[1]; }