Fix the signature of the IndexOf entry point.

The IndexOf entry point was declared as taking four
arguments (void*, uint32_t, uint32_t, uint32_t) whereas all
actual implementations use three arguments (void*, uint32_t,
uint32_t).  As that fourth argument is not documented, drop
it from the intrinsic declaration to have it match the
implementations.

Change-Id: I65d747033192025ccd2b9a5e8f8ed05b77a21941
diff --git a/compiler/optimizing/intrinsics_arm.cc b/compiler/optimizing/intrinsics_arm.cc
index 4ce919e..a9da5fa 100644
--- a/compiler/optimizing/intrinsics_arm.cc
+++ b/compiler/optimizing/intrinsics_arm.cc
@@ -1151,6 +1151,7 @@
 
   __ LoadFromOffset(kLoadWord, LR, TR,
                     QUICK_ENTRYPOINT_OFFSET(kArmWordSize, pIndexOf).Int32Value());
+  CheckEntrypointTypes<kQuickIndexOf, int32_t, void*, uint32_t, uint32_t>();
   __ blx(LR);
 
   if (slow_path != nullptr) {