Fix several bugs in compaction:

src/flag-definitions.h

 // Copyright 2011 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 234 matching lines @@
 DEFINE_int(gc_interval, -1, "garbage collect after <n> allocations")
 DEFINE_bool(trace_gc, false,
             "print one trace line following each garbage collection")
 DEFINE_bool(trace_gc_nvp, false,
             "print one detailed trace line in name=value format "
             "after each garbage collection")
 DEFINE_bool(print_cumulative_gc_stat, false,
             "print cumulative GC statistics in name=value format on exit")
 DEFINE_bool(trace_gc_verbose, false,
             "print more details following each garbage collection")
+DEFINE_bool(trace_fragmentation, false,
+            "report fragmentation for old pointer and data pages")
 DEFINE_bool(collect_maps, true,
             "garbage collect maps from which no objects can be reached")
 DEFINE_bool(flush_code, false,
             "flush code that we expect not to use again before full gc")
 #ifdef V8_TARGET_ARCH_ARM
 DEFINE_bool(incremental_marking, false, "use incremental marking")
 #else
 DEFINE_bool(incremental_marking, true, "use incremental marking")
 #endif
 DEFINE_bool(incremental_marking_steps, true, "do incremental marking steps")
@@ skipping 185 matching lines @@
 DEFINE_bool(trace_lazy, false, "trace lazy compilation")
 
 // serialize.cc
 DEFINE_bool(debug_serialization, false,
             "write debug information into the snapshot.")
 
 // spaces.cc
 DEFINE_bool(collect_heap_spill_statistics, false,
             "report heap spill statistics along with heap_stats "
             "(requires heap_stats)")
-DEFINE_bool(trace_fragmentation, false,
-            "report fragmentation for old pointer and data pages")
 
 DEFINE_bool(trace_isolates, false, "trace isolate state changes")
 
 // VM state
 DEFINE_bool(log_state_changes, false, "Log state changes.")
 
 // Regexp
 DEFINE_bool(regexp_possessive_quantifier,
             false,
             "enable possessive quantifier syntax for testing")
@@ skipping 64 matching lines @@
 #undef FLAG
 
 #undef DEFINE_bool
 #undef DEFINE_int
 #undef DEFINE_string
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META