MIPS64: Improve integer division by constants

This also removes some unused instructions and instructions not
available on MIPS64R6.

Change-Id: I44bfe12c60344312c88c45e97b6b07dcd5bdc630
diff --git a/compiler/optimizing/code_generator_mips64.h b/compiler/optimizing/code_generator_mips64.h
index 4f91c71..58c6e0f 100644
--- a/compiler/optimizing/code_generator_mips64.h
+++ b/compiler/optimizing/code_generator_mips64.h
@@ -230,6 +230,10 @@
                              Label* true_target,
                              Label* false_target,
                              Label* always_true_target);
+  void DivRemOneOrMinusOne(HBinaryOperation* instruction);
+  void DivRemByPowerOfTwo(HBinaryOperation* instruction);
+  void GenerateDivRemWithAnyConstant(HBinaryOperation* instruction);
+  void GenerateDivRemIntegral(HBinaryOperation* instruction);
   void HandleGoto(HInstruction* got, HBasicBlock* successor);
 
   Mips64Assembler* const assembler_;