A64: Synchronize with r18642.

src/a64/code-stubs-a64.h

Index: src/a64/code-stubs-a64.h
diff --git a/src/a64/code-stubs-a64.h b/src/a64/code-stubs-a64.h
index 08d9b66c48ff55077e2220256cc4bd7392db33cf..ade5de67355eeb0e16be5683c6e507a71b46a633 100644
--- a/src/a64/code-stubs-a64.h
+++ b/src/a64/code-stubs-a64.h
@@ -501,6 +501,18 @@ class StringCompareStub: public PlatformCodeStub {
 };
 
 
+struct PlatformCallInterfaceDescriptor {
+  explicit PlatformCallInterfaceDescriptor(
+      TargetAddressStorageMode storage_mode)
+      : storage_mode_(storage_mode) { }
+
+  TargetAddressStorageMode storage_mode() { return storage_mode_; }
+
+ private:
+  TargetAddressStorageMode storage_mode_;
+};
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_A64_CODE_STUBS_A64_H_