Support inlining function containing throw in the optimizer.

runtime/vm/il_printer.cc

Index: runtime/vm/il_printer.cc
===================================================================
--- runtime/vm/il_printer.cc	(revision 23006)
+++ runtime/vm/il_printer.cc	(working copy)
@@ -862,6 +862,14 @@
 
 void TargetEntryInstr::PrintTo(BufferFormatter* f) const {
   f->Print("B%"Pd"[target]:%"Pd, block_id(), GetDeoptId());
+  if (PredecessorCount() > 0) {
+    f->Print(" pred(");
+    for (intptr_t i = 0; i < PredecessorCount(); ++i) {
+      if (i > 0) f->Print(", ");
+      f->Print("B%"Pd, PredecessorAt(i)->block_id());
+    }
+    f->Print(")");
+  }
   if (HasParallelMove()) {
     f->Print(" ");
     parallel_move()->PrintTo(f);