Optimize expressions of the form (expr === true) when expr has boolean type.

vm/compiler.cc

Index: vm/compiler.cc
===================================================================
--- vm/compiler.cc	(revision 10497)
+++ vm/compiler.cc	(working copy)
@@ -178,6 +178,9 @@
         FlowGraphTypePropagator propagator(parsed_function, block_order);
         propagator.PropagateTypes();
 
+        // Do optimizations that depend on the propagated type information.
+        optimizer.OptimizeComputations();
+
         if (use_ssa) {
           // Perform register allocation on the SSA graph.
           FlowGraphAllocator allocator(block_order, &graph_builder);
@@ -387,8 +390,7 @@
     }
     if (FLAG_disassemble) {
       DisassembleCode(function, optimized);
-    }
-    if (FLAG_disassemble_optimized && optimized) {
+    } else if (FLAG_disassemble_optimized && optimized) {
       // Print unoptimized code along with the optimized code.
       DisassembleCode(function, false);
       DisassembleCode(function, true);