Add conditional expressions (ternary choice operator) to fast compiler.

src/compiler.cc

Index: src/compiler.cc
===================================================================
--- src/compiler.cc	(revision 3191)
+++ src/compiler.cc	(working copy)
@@ -625,7 +625,11 @@
 
 
 void CodeGenSelector::VisitConditional(Conditional* expr) {
-  BAILOUT("Conditional");
+  ProcessExpression(expr->condition(), Expression::kTest);
+  CHECK_BAILOUT;
+  ProcessExpression(expr->then_expression(), context_);
+  CHECK_BAILOUT;
+  ProcessExpression(expr->else_expression(), context_);
 }