[strong] Fix inlining issue

src/arm/lithium-arm.h

Index: src/arm/lithium-arm.h
diff --git a/src/arm/lithium-arm.h b/src/arm/lithium-arm.h
index 66df46a3bd184b4d628608dcfa7b1496397dd057..e0d4293ee3060403a03b8bfa9ed028668956ebd7 100644
--- a/src/arm/lithium-arm.h
+++ b/src/arm/lithium-arm.h
@@ -1565,6 +1565,10 @@ class LArithmeticT final : public LTemplateInstruction<1, 3, 0> {
   void CompileToNative(LCodeGen* generator) override;
   const char* Mnemonic() const override;
 
+  DECLARE_HYDROGEN_ACCESSOR(BinaryOperation)
+
+  LanguageMode language_mode() { return hydrogen()->language_mode(); }
+
  private:
   Token::Value op_;
 };