A64: Fix addition of external value and int32.

src/a64/lithium-a64.h

Index: src/a64/lithium-a64.h
diff --git a/src/a64/lithium-a64.h b/src/a64/lithium-a64.h
index 208f65e8330de814c10229367831ae479d722acd..dddb0ad009e7ea50f171f40bda26faf093819aea 100644
--- a/src/a64/lithium-a64.h
+++ b/src/a64/lithium-a64.h
@@ -42,6 +42,7 @@ class LCodeGen;
 
 #define LITHIUM_CONCRETE_INSTRUCTION_LIST(V)    \
   V(AccessArgumentsAt)                          \
+  V(AddE)                                       \
   V(AddI)                                       \
   V(AddS)                                       \
   V(Allocate)                                   \
@@ -562,6 +563,21 @@ class LAccessArgumentsAt V8_FINAL : public LTemplateInstruction<1, 3, 1> {
 };
 
 
+class LAddE V8_FINAL : public LTemplateInstruction<1, 2, 0> {
+ public:
+  LAddE(LOperand* left, LOperand* right) {
+    inputs_[0] = left;
+    inputs_[1] = right;
+  }
+
+  LOperand* left() { return inputs_[0]; }
+  LOperand* right() { return inputs_[1]; }
+
+  DECLARE_CONCRETE_INSTRUCTION(AddE, "add-e")
+  DECLARE_HYDROGEN_ACCESSOR(Add)
+};
+
+
 class LAddI V8_FINAL : public LTemplateInstruction<1, 2, 0> {
  public:
   LAddI(LOperand* left, LOperand* right) {