Mitigate windows crash & failure by disabling merging of sin & cos.

runtime/vm/flow_graph_optimizer.cc

 // Copyright (c) 2013, 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.
 
 #include "vm/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/cpu.h"
 #include "vm/dart_entry.h"
@@ skipping 15 matching lines @@
 
 DEFINE_FLAG(int, getter_setter_ratio, 13,
     "Ratio of getter/setter usage used for double field unboxing heuristics");
 DEFINE_FLAG(bool, load_cse, true, "Use redundant load elimination.");
 DEFINE_FLAG(bool, dead_store_elimination, true, "Eliminate dead stores");
 DEFINE_FLAG(int, max_polymorphic_checks, 4,
     "Maximum number of polymorphic check, otherwise it is megamorphic.");
 DEFINE_FLAG(int, max_equality_polymorphic_checks, 32,
     "Maximum number of polymorphic checks in equality operator,"
     " otherwise use megamorphic dispatch.");
-DEFINE_FLAG(bool, merge_sin_cos, true, "Merge sin/cos into sincos");
+DEFINE_FLAG(bool, merge_sin_cos, false, "Merge sin/cos into sincos");
 DEFINE_FLAG(bool, trace_load_optimization, false,
     "Print live sets for load optimization pass.");
 DEFINE_FLAG(bool, trace_optimization, false, "Print optimization details.");
 DEFINE_FLAG(bool, truncating_left_shift, true,
     "Optimize left shift to truncate if possible");
 DEFINE_FLAG(bool, use_cha, true, "Use class hierarchy analysis.");
 #if defined(TARGET_ARCH_ARM) || defined(TARGET_ARCH_IA32)
 DEFINE_FLAG(bool, trace_smi_widening, false, "Trace Smi->Int32 widening pass.");
 #endif
 DECLARE_FLAG(bool, enable_type_checks);
@@ skipping 8563 matching lines @@
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits_collector_.exits().length(); i++) {
     CreateMaterializationAt(
         exits_collector_.exits()[i], alloc, *slots);
   }
 }
 
 
 }  // namespace dart