Allow enabling --causal-async-stacks in AOT.

runtime/vm/flag_list.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_VM_FLAG_LIST_H_
 #define RUNTIME_VM_FLAG_LIST_H_
 
 // Don't use USING_DBC outside of this file.
 #if defined(TARGET_ARCH_DBC)
 #define USING_DBC true
 #else
 #define USING_DBC false
 #endif
 
 // Don't use USING_MULTICORE outside of this file.
 #if defined(ARCH_IS_MULTI_CORE)
 #define USING_MULTICORE true
 #else
 #define USING_MULTICORE false
 #endif
 
+// Don't use USING_PRODUCT outside of this file.
+#if defined(PRODUCT)
+#define USING_PRODUCT true
+#else
+#define USING_PRODUCT false
+#endif
+
 // List of all flags in the VM.
 // Flags can be one of three categories:
 // * P roduct flags: Can be set in any of the deployment modes, including in
 //   production.
 // * R elease flags: Generally available flags except when building product.
 // * D ebug flags: Can only be set in debug VMs, which also have C++ assertions
 //   enabled.
 // * pre C ompile flags: Generally available flags except when building product
 //   or precompiled runtime.
 //
@@ skipping 95 matching lines @@
     "Attempt to print a native stack trace when an API error is created.")     \
   C(print_stop_message, false, false, bool, false, "Print stop message.")      \
   D(print_variable_descriptors, bool, false,                                   \
     "Print variable descriptors in disassembly.")                              \
   R(profiler, false, bool, !USING_DBC, "Enable the profiler.")                 \
   R(profiler_native_memory, false, bool, false,                                \
     "Enable native memory statistic collection.")                              \
   P(reify_generic_functions, bool, false,                                      \
     "Enable reification of generic functions (not yet supported).")            \
   P(reorder_basic_blocks, bool, true, "Reorder basic blocks")                  \
-  C(causal_async_stacks, false, false, bool, true, "Improved async stacks")    \
+  P(causal_async_stacks, bool, !USING_PRODUCT, "Improved async stacks")        \
   C(stress_async_stacks, false, false, bool, false,                            \
     "Stress test async stack traces")                                          \
   C(async_debugger, false, false, bool, true,                                  \
     "Debugger support async functions.")                                       \
   R(support_ast_printer, false, bool, true, "Support the AST printer.")        \
   R(support_compiler_stats, false, bool, true, "Support compiler stats.")      \
   C(support_debugger, false, false, bool, true, "Support the debugger.")       \
   R(support_disassembler, false, bool, true, "Support the disassembler.")      \
   R(support_il_printer, false, bool, true, "Support the IL printer.")          \
   C(support_reload, false, false, bool, true, "Support isolate reload.")       \
@@ skipping 20 matching lines @@
   P(verbose_gc_hdr, int, 40, "Print verbose GC header interval.")              \
   R(verify_after_gc, false, bool, false,                                       \
     "Enables heap verification after GC.")                                     \
   R(verify_before_gc, false, bool, false,                                      \
     "Enables heap verification before GC.")                                    \
   D(verify_gc_contains, bool, false,                                           \
     "Enables verification of address contains during GC.")                     \
   D(verify_on_transition, bool, false, "Verify on dart <==> VM.")
 
 #endif  // RUNTIME_VM_FLAG_LIST_H_