Add rep movsw to x86 and x86_64 instructions.

Add 'REP MOVSW' as a supported instruction for x86 32 and 64 bit.

Added tests.

Change-Id: I1c615ac1e7fa46c48983c90f791b92be0375c8b8
Signed-off-by: Mark Mendell <mark.p.mendell@intel.com>
diff --git a/compiler/utils/x86/assembler_x86_test.cc b/compiler/utils/x86/assembler_x86_test.cc
index b664d23..c257b78 100644
--- a/compiler/utils/x86/assembler_x86_test.cc
+++ b/compiler/utils/x86/assembler_x86_test.cc
@@ -218,4 +218,16 @@
   DriverStr(expected, "Repecmpsl");
 }
 
+TEST_F(AssemblerX86Test, RepneScasw) {
+  GetAssembler()->repne_scasw();
+  const char* expected = "repne scasw\n";
+  DriverStr(expected, "repne_scasw");
+}
+
+TEST_F(AssemblerX86Test, RepMovsw) {
+  GetAssembler()->rep_movsw();
+  const char* expected = "rep movsw\n";
+  DriverStr(expected, "rep_movsw");
+}
+
 }  // namespace art