Implement global check elimination using the HFlowEngine.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 3b232e6e93ee2d307e5ea9504266825fb9f11b36..7e48a60eed72c3831dfa87b7968e0ca66664d1fb 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -3138,7 +3138,6 @@ bool HGraph::Optimize(BailoutReason* bailout_reason) {
   // where unreachable code could unnecessarily defeat LICM.
   Run<HMarkUnreachableBlocksPhase>();
 
-  if (FLAG_check_elimination) Run<HCheckEliminationPhase>();
   if (FLAG_dead_code_elimination) Run<HDeadCodeEliminationPhase>();
   if (FLAG_use_escape_analysis) Run<HEscapeAnalysisPhase>();
 
@@ -3169,6 +3168,8 @@ bool HGraph::Optimize(BailoutReason* bailout_reason) {
 
   if (FLAG_use_gvn) Run<HGlobalValueNumberingPhase>();
 
+  if (FLAG_check_elimination) Run<HCheckEliminationPhase>();
+
   if (FLAG_use_range) Run<HRangeAnalysisPhase>();
 
   Run<HComputeChangeUndefinedToNaN>();