Introduce exception object and remove some uses of MaybeObject::IsFailure().

src/heap.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 42 matching lines @@
   V(Map, one_pointer_filler_map, OnePointerFillerMap)                          \
   V(Map, two_pointer_filler_map, TwoPointerFillerMap)                          \
   /* Cluster the most popular ones in a few cache lines here at the top.    */ \
   V(Smi, store_buffer_top, StoreBufferTop)                                     \
   V(Oddball, undefined_value, UndefinedValue)                                  \
   V(Oddball, the_hole_value, TheHoleValue)                                     \
   V(Oddball, null_value, NullValue)                                            \
   V(Oddball, true_value, TrueValue)                                            \
   V(Oddball, false_value, FalseValue)                                          \
   V(Oddball, uninitialized_value, UninitializedValue)                          \
+  V(Oddball, exception, Exception)                                             \
   V(Map, cell_map, CellMap)                                                    \
   V(Map, global_property_cell_map, GlobalPropertyCellMap)                      \
   V(Map, shared_function_info_map, SharedFunctionInfoMap)                      \
   V(Map, meta_map, MetaMap)                                                    \
   V(Map, heap_number_map, HeapNumberMap)                                       \
   V(Map, native_context_map, NativeContextMap)                                 \
   V(Map, fixed_array_map, FixedArrayMap)                                       \
   V(Map, code_map, CodeMap)                                                    \
   V(Map, scope_info_map, ScopeInfoMap)                                         \
   V(Map, fixed_cow_array_map, FixedCOWArrayMap)                                \
@@ skipping 107 matching lines @@
   V(Map, block_context_map, BlockContextMap)                                   \
   V(Map, module_context_map, ModuleContextMap)                                 \
   V(Map, global_context_map, GlobalContextMap)                                 \
   V(Map, undefined_map, UndefinedMap)                                          \
   V(Map, the_hole_map, TheHoleMap)                                             \
   V(Map, null_map, NullMap)                                                    \
   V(Map, boolean_map, BooleanMap)                                              \
   V(Map, uninitialized_map, UninitializedMap)                                  \
   V(Map, arguments_marker_map, ArgumentsMarkerMap)                             \
   V(Map, no_interceptor_result_sentinel_map, NoInterceptorResultSentinelMap)   \
+  V(Map, exception_map, ExceptionMap)                                          \
   V(Map, termination_exception_map, TerminationExceptionMap)                   \
   V(Map, message_object_map, JSMessageObjectMap)                               \
   V(Map, foreign_map, ForeignMap)                                              \
   V(HeapNumber, nan_value, NanValue)                                           \
   V(HeapNumber, infinity_value, InfinityValue)                                 \
   V(HeapNumber, minus_zero_value, MinusZeroValue)                              \
   V(Map, neander_map, NeanderMap)                                              \
   V(JSObject, message_listeners, MessageListeners)                             \
   V(UnseededNumberDictionary, code_stubs, CodeStubs)                           \
   V(UnseededNumberDictionary, non_monomorphic_cache, NonMonomorphicCache)      \
@@ skipping 2695 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_