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/assembler_x86.h b/compiler/utils/x86/assembler_x86.h
index e2abcde..ae8d7a1 100644
--- a/compiler/utils/x86/assembler_x86.h
+++ b/compiler/utils/x86/assembler_x86.h
@@ -466,6 +466,7 @@
 
   void repne_scasw();
   void repe_cmpsw();
+  void repe_cmpsl();
 
   X86Assembler* lock();
   void cmpxchgl(const Address& address, Register reg);