Merged r12362 into 3.12 branch.

src/x64/lithium-codegen-x64.h

Index: src/x64/lithium-codegen-x64.h
diff --git a/src/x64/lithium-codegen-x64.h b/src/x64/lithium-codegen-x64.h
index 57833744356fa73766b0383468f9801e2ef81dc8..21486efe2c408fa77f6dea97a5c7757312aa1caa 100644
--- a/src/x64/lithium-codegen-x64.h
+++ b/src/x64/lithium-codegen-x64.h
@@ -271,6 +271,11 @@ class LCodeGen BASE_EMBEDDED {
                         bool deoptimize_on_minus_zero,
                         LEnvironment* env);
 
+
+  void DeoptIfTaggedButNotSmi(LEnvironment* environment,
+                              HValue* value,
+                              LOperand* operand);
+
   // Emits optimized code for typeof x == "y".  Modifies input register.
   // Returns the condition on which a final split to
   // true and false label should be made, to optimize fallthrough.