Fix bug with optimized try-catch and unboxed values.

runtime/vm/intermediate_language.cc

Index: runtime/vm/intermediate_language.cc
===================================================================
--- runtime/vm/intermediate_language.cc	(revision 36427)
+++ runtime/vm/intermediate_language.cc	(working copy)
@@ -1634,8 +1634,20 @@
 }
 
 
+static bool HasTryBlockUse(Value* use_list) {
+  for (Value::Iterator it(use_list); !it.Done(); it.Advance()) {
+    Value* use = it.Current();
+    if (use->instruction()->MayThrow() &&
+        use->instruction()->GetBlock()->InsideTryBlock()) {
+      return true;
+    }
+  }
+  return false;
+}
+
+
 Definition* BoxDoubleInstr::Canonicalize(FlowGraph* flow_graph) {
-  if (input_use_list() == NULL) {
+  if ((input_use_list() == NULL) && !HasTryBlockUse(env_use_list())) {
     // Environments can accomodate any representation. No need to box.
     return value()->definition();
   }
@@ -1670,7 +1682,7 @@
 
 
 Definition* BoxFloat32x4Instr::Canonicalize(FlowGraph* flow_graph) {
-  if (input_use_list() == NULL) {
+  if ((input_use_list() == NULL) && !HasTryBlockUse(env_use_list())) {
     // Environments can accomodate any representation. No need to box.
     return value()->definition();
   }
@@ -1693,7 +1705,7 @@
 
 
 Definition* BoxFloat64x2Instr::Canonicalize(FlowGraph* flow_graph) {
-  if (input_use_list() == NULL) {
+  if ((input_use_list() == NULL) && !HasTryBlockUse(env_use_list())) {
     // Environments can accomodate any representation. No need to box.
     return value()->definition();
   }
@@ -1717,7 +1729,7 @@
 
 
 Definition* BoxInt32x4Instr::Canonicalize(FlowGraph* flow_graph) {
-  if (input_use_list() == NULL) {
+  if ((input_use_list() == NULL) && !HasTryBlockUse(env_use_list())) {
     // Environments can accomodate any representation. No need to box.
     return value()->definition();
   }