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 5b9e42f9979195104780f8c89e5cb5ca061b8932..133caea30e478f9ced5507a3a451cfc0d85c8ce4 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -3771,7 +3771,6 @@ 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>();
 
@@ -3802,6 +3801,8 @@ 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>();