Added repe_cmpsl instruction to x86, x86_64 assemblers

Support for this instruction has already been added to the disassembler
in commit 124b392d.

Change-Id: I6e8401a7b814618758427f5cc6b4992e265f937c
diff --git a/compiler/utils/x86_64/assembler_x86_64.h b/compiler/utils/x86_64/assembler_x86_64.h
index 0cd3197..89a5606 100644
--- a/compiler/utils/x86_64/assembler_x86_64.h
+++ b/compiler/utils/x86_64/assembler_x86_64.h
@@ -604,6 +604,7 @@
 
   void repne_scasw();
   void repe_cmpsw();
+  void repe_cmpsl();
 
   //
   // Macros for High-level operations.