Use type info for the ToBoolean translation in crankshaft.

src/ia32/lithium-ia32.cc

Index: src/ia32/lithium-ia32.cc
===================================================================
--- src/ia32/lithium-ia32.cc	(revision 8757)
+++ src/ia32/lithium-ia32.cc	(working copy)
@@ -1041,7 +1041,11 @@
         : instr->SecondSuccessor();
     return new LGoto(successor->block_id());
   }
-  return new LBranch(UseRegisterAtStart(v));
+  ToBooleanStub::Types expected = instr->expected_input_types();
+  bool needs_temp = expected.NeedsMap() || expected.IsEmpty();
+  LOperand* temp = needs_temp ? TempRegister() : NULL;
+  LInstruction* branch = new LBranch(UseRegister(v), temp);
+  return AssignEnvironment(branch);

[fschneider, 2011/07/28 13:54:58]

If we cover all cases, then we don't deopt, right? In this case you can avoid
assigning an environment to reduce the number of live values.

 }