Enables per-function far-branches for ARM and MIPS.

runtime/vm/flow_graph.h

Index: runtime/vm/flow_graph.h
===================================================================
--- runtime/vm/flow_graph.h	(revision 25720)
+++ runtime/vm/flow_graph.h	(working copy)
@@ -41,7 +41,7 @@
 };
 
 
-// Class to incapsulate the construction and manipulation of the flow graph.
+// Class to encapsulate the construction and manipulation of the flow graph.
 class FlowGraph : public ZoneAllocated {
  public:
   FlowGraph(const FlowGraphBuilder& builder,
@@ -163,6 +163,11 @@
   // after this point.
   void disallow_licm() { licm_allowed_ = false; }
 
+  bool use_far_branches() const { return use_far_branches_; }
+  void set_use_far_branches(bool value) {
+    use_far_branches_ = value;
+  }
+
   const ZoneGrowableArray<BlockEntryInstr*>& loop_headers() {
     if (loop_headers_ == NULL) {
       loop_headers_ = ComputeLoops();
@@ -249,6 +254,8 @@
   BlockEffects* block_effects_;
   bool licm_allowed_;
 
+  bool use_far_branches_;
+
   ZoneGrowableArray<BlockEntryInstr*>* loop_headers_;
   ZoneGrowableArray<BitVector*>* loop_invariant_loads_;
 };