Remove broken %_Log functionality.

src/mips/macro-assembler-mips.h

Index: src/mips/macro-assembler-mips.h
diff --git a/src/mips/macro-assembler-mips.h b/src/mips/macro-assembler-mips.h
index 5c20a1514b4cac98a93983ccb2b9077e73c2dd70..acf62f25b56213162ae65f3ea6db153df7d13957 100644
--- a/src/mips/macro-assembler-mips.h
+++ b/src/mips/macro-assembler-mips.h
@@ -1048,10 +1048,6 @@ class MacroAssembler: public Assembler {
                    Handle<Code> success,
                    SmiCheckType smi_check_type);
 
-  // Generates code for reporting that an illegal operation has
-  // occurred.
-  void IllegalOperation(int num_arguments);
-
 
   // Load and check the instance type of an object for being a string.
   // Loads the type into the second argument register.