Fix product build break.

runtime/vm/compiler.cc

Index: runtime/vm/compiler.cc
diff --git a/runtime/vm/compiler.cc b/runtime/vm/compiler.cc
index 4504717e31ba2cf1ac8e8b65db78bbb0f7f9b33e..25fad986f195719a9875322bf279c3cd151dbf7f 100644
--- a/runtime/vm/compiler.cc
+++ b/runtime/vm/compiler.cc
@@ -1411,12 +1411,14 @@ static RawError* ParseFunctionHelper(CompilationPipeline* pipeline,
     // For now we just walk thru the AST nodes and in DEBUG mode we print
     // them otherwise just skip through them, this will be need to be
     // wired to generate the IR format.
+#if !defined(PRODUCT)
 #if defined(DEBUG)
     AstPrinter ast_printer(true);
 #else
     AstPrinter ast_printer(false);
 #endif  // defined(DEBUG).
     ast_printer.PrintFunctionNodes(*parsed_function);
+#endif  // !defined(PRODUCT).
     return Error::null();
   } else {
     Thread* const thread = Thread::Current();