Deprecate semi-correct CompilationInfo::flags predicate.

src/compiler.cc

Index: src/compiler.cc
diff --git a/src/compiler.cc b/src/compiler.cc
index 76c70acd300cf783be181663ea67b629bec32233..9ce666c911a3edb95498371c81fee474ed993121 100644
--- a/src/compiler.cc
+++ b/src/compiler.cc
@@ -215,15 +215,6 @@ int CompilationInfo::num_heap_slots() const {
 }
 
 
-Code::Flags CompilationInfo::flags() const {
-  return code_stub() != nullptr
-             ? Code::ComputeFlags(
-                   code_stub()->GetCodeKind(), code_stub()->GetICState(),
-                   code_stub()->GetExtraICState(), code_stub()->GetStubType())
-             : Code::ComputeFlags(Code::OPTIMIZED_FUNCTION);
-}
-
-
 // Primitive functions are unlikely to be picked up by the stack-walking
 // profiler, so they trigger their own optimization when they're called
 // for the SharedFunctionInfo::kCallsUntilPrimitiveOptimization-th time.