Option to truncate integers to 64 bits, part 1 (core VM changes)

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
@@ skipping 76 matching lines @@
   R(gc_at_alloc, false, bool, false, "GC at every allocation.")                \
   P(getter_setter_ratio, int, 13,                                              \
     "Ratio of getter/setter usage used for double field unboxing heuristics")  \
   P(guess_icdata_cid, bool, true,                                              \
     "Artificially create type feedback for arithmetic etc. operations")        \
   P(huge_method_cutoff_in_tokens, int, 20000,                                  \
     "Huge method cutoff in tokens: Disables optimizations for huge methods.")  \
   P(interpret_irregexp, bool, USING_DBC, "Use irregexp bytecode interpreter")  \
   P(lazy_dispatchers, bool, true, "Generate dispatchers lazily")               \
   P(link_natives_lazily, bool, false, "Link native calls lazily")              \
-  R(limit_ints_to_64_bits, false, bool, false,                                 \
-    "Throw a RangeError on 64-bit integer overflow");                          \
+  R(limit_ints_to_64_bits, false, bool, false, "Truncate integers to 64 bits") \
   C(load_deferred_eagerly, true, true, bool, false,                            \
     "Load deferred libraries eagerly.")                                        \
   R(log_marker_tasks, false, bool, false,                                      \
     "Log debugging information for old gen GC marking tasks.")                 \
   R(marker_tasks, USING_MULTICORE ? 2 : 0, int, USING_MULTICORE ? 2 : 0,       \
     "The number of tasks to spawn during old gen GC marking (0 means "         \
     "perform all marking on main thread).")                                    \
   P(max_polymorphic_checks, int, 4,                                            \
     "Maximum number of polymorphic check, otherwise it is megamorphic.")       \
   P(max_equality_polymorphic_checks, int, 32,                                  \
@@ skipping 66 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_