ART: x86 indexOf intrinsics for the optimizing compiler

Add intrinsics implementations for indexOf in the optimizing
compiler. These are mostly ported from Quick. Add instruction
support to assemblers where necessary.

Change-Id: Ife90ed0245532a5c436a26fe84715dc357f353c8
diff --git a/compiler/utils/x86/assembler_x86_test.cc b/compiler/utils/x86/assembler_x86_test.cc
index f326e49..aacc57b 100644
--- a/compiler/utils/x86/assembler_x86_test.cc
+++ b/compiler/utils/x86/assembler_x86_test.cc
@@ -190,4 +190,10 @@
   DriverStr(expected, "FPUIntegerStore");
 }
 
+TEST_F(AssemblerX86Test, Repnescasw) {
+  GetAssembler()->repne_scasw();
+  const char* expected = "repne scasw\n";
+  DriverStr(expected, "Repnescasw");
+}
+
 }  // namespace art