Convert diamond shaped control flow into a single conditional instruction.

runtime/vm/compiler.cc

Index: runtime/vm/compiler.cc
diff --git a/runtime/vm/compiler.cc b/runtime/vm/compiler.cc
index 463dfa76cd1490853c55b27d49f99221c4851d23..e39278b99998bd9d0b680f437964ca3427687bb2 100644
--- a/runtime/vm/compiler.cc
+++ b/runtime/vm/compiler.cc
@@ -215,6 +215,9 @@ static bool CompileParsedFunctionHelper(const ParsedFunction& parsed_function,
       BranchSimplifier::Simplify(flow_graph);
       DEBUG_ASSERT(flow_graph->VerifyUseLists());
 
+      IfConverter::Simplify(flow_graph);
+      DEBUG_ASSERT(flow_graph->VerifyUseLists());
+
       if (FLAG_constant_propagation) {
         ConstantPropagator::Optimize(flow_graph);
         DEBUG_ASSERT(flow_graph->VerifyUseLists());