Fix vm code base so that it can be built for --arch=simarm (no snapshot yet).

runtime/vm/flow_graph_optimizer.cc

Index: runtime/vm/flow_graph_optimizer.cc
===================================================================
--- runtime/vm/flow_graph_optimizer.cc	(revision 17160)
+++ runtime/vm/flow_graph_optimizer.cc	(working copy)
@@ -1311,9 +1311,14 @@
     }
     if ((recognized_kind == MethodRecognizer::kDoubleTruncate) ||
         (recognized_kind == MethodRecognizer::kDoubleRound)) {
+#if defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_X64)
+      // TODO(regis): FlowGraphOptimizer should be architecture dependent.
       if (!CPUFeatures::sse4_1_supported()) {
         return false;
       }
+#else
+      return false;
+#endif
       AddCheckClass(call, call->ArgumentAt(0)->value()->Copy());
       DoubleToDoubleInstr* d2d_instr =
           new DoubleToDoubleInstr(call->ArgumentAt(0)->value(),
@@ -2001,11 +2006,20 @@
   GrowableArray<Definition*> worklist_;
   BitVector* marked_defns_;
 
-  class ArrayLengthData : public ValueObject {
+  class ArrayLengthData {
    public:
     ArrayLengthData(Definition* array, Definition* array_length)
         : array_(array), array_length_(array_length) { }
 
+    ArrayLengthData(const ArrayLengthData& other)
+        : array_(other.array_), array_length_(other.array_length_) { }
+
+    ArrayLengthData& operator=(const ArrayLengthData& other) {
+      array_ = other.array_;
+      array_length_ = other.array_length_;
+      return *this;
+    }
+
     Definition* array() const { return array_; }
     Definition* array_length() const { return array_length_; }