ART: Disable Math.round intrinsics

The move to OpenJDK means that Android has caught up with the
definition change of Math.round. Disable intrinsics.

Bug: 26327751
Change-Id: I00dc6cfca12bd7c95e56a4ab76ffee707d3822dc
diff --git a/compiler/optimizing/intrinsics_x86.cc b/compiler/optimizing/intrinsics_x86.cc
index 8019062..677f2e9 100644
--- a/compiler/optimizing/intrinsics_x86.cc
+++ b/compiler/optimizing/intrinsics_x86.cc
@@ -720,6 +720,11 @@
 // Note that 32 bit x86 doesn't have the capability to inline MathRoundDouble,
 // as it needs 64 bit instructions.
 void IntrinsicLocationsBuilderX86::VisitMathRoundFloat(HInvoke* invoke) {
+  // See intrinsics.h.
+  if (!kRoundIsPlusPointFive) {
+    return;
+  }
+
   // Do we have instruction support?
   if (codegen_->GetInstructionSetFeatures().HasSSE4_1()) {
     LocationSummary* locations = new (arena_) LocationSummary(invoke,