VM: Remove dead code from flow graph optimizer.

runtime/vm/precompiler.cc

Index: runtime/vm/precompiler.cc
diff --git a/runtime/vm/precompiler.cc b/runtime/vm/precompiler.cc
index 30fb89034e694df1a7ef7779a18b65e6757b3544..ee8cf41e4c986ac634b21ccae2291e853786b9d0 100644
--- a/runtime/vm/precompiler.cc
+++ b/runtime/vm/precompiler.cc
@@ -22,6 +22,7 @@
 #include "vm/flow_graph_compiler.h"
 #include "vm/flow_graph_inliner.h"
 #include "vm/flow_graph_optimizer.h"
+#include "vm/flow_graph_range_analysis.h"
 #include "vm/flow_graph_type_propagator.h"
 #include "vm/hash_table.h"
 #include "vm/il_printer.h"
@@ -1917,7 +1918,8 @@ bool PrecompileParsedFunctionHelper::Compile(CompilationPipeline* pipeline) {
           // We have to perform range analysis after LICM because it
           // optimistically moves CheckSmi through phis into loop preheaders
           // making some phis smi.
-          optimizer.InferIntRanges();
+          RangeAnalysis range_analysis(flow_graph);
+          range_analysis.Analyze();
           DEBUG_ASSERT(flow_graph->VerifyUseLists());
         }