[runtime] Remove the redundant %_IsObject intrinsic.

src/ppc/lithium-codegen-ppc.h

Index: src/ppc/lithium-codegen-ppc.h
diff --git a/src/ppc/lithium-codegen-ppc.h b/src/ppc/lithium-codegen-ppc.h
index 392bbf587263590b8166d483f9805eaab0acf47a..7f808fe7c7c1c8b82d338dde8f5da66a609d1c25 100644
--- a/src/ppc/lithium-codegen-ppc.h
+++ b/src/ppc/lithium-codegen-ppc.h
@@ -254,12 +254,6 @@ class LCodeGen : public LCodeGenBase {
   Condition EmitTypeofIs(Label* true_label, Label* false_label, Register input,
                          Handle<String> type_name);
 
-  // Emits optimized code for %_IsObject(x).  Preserves input register.
-  // Returns the condition on which a final split to
-  // true and false label should be made, to optimize fallthrough.
-  Condition EmitIsObject(Register input, Register temp1, Label* is_not_object,
-                         Label* is_object);
-
   // Emits optimized code for %_IsString(x).  Preserves input register.
   // Returns the condition on which a final split to
   // true and false label should be made, to optimize fallthrough.