Remove scratch register requirement from LoadInstanceDescriptors on arm and mips.

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 a13c8ecf2da48516be2ad6b2ddbcb8268885e0cc..b57e51486c510b9391814a60ac460acb48522eaa 100644
--- a/src/mips/macro-assembler-mips.h
+++ b/src/mips/macro-assembler-mips.h
@@ -1398,9 +1398,7 @@ class MacroAssembler: public Assembler {
                           DoubleRegister temp_double_reg);
 
 
-  void LoadInstanceDescriptors(Register map,
-                               Register descriptors,
-                               Register scratch);
+  void LoadInstanceDescriptors(Register map, Register descriptors);
   void EnumLength(Register dst, Register map);
   void NumberOfOwnDescriptors(Register dst, Register map);