Implement verification of context separation.

src/flag-definitions.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 534 matching lines @@
 
 // contexts.cc
 DEFINE_bool(trace_contexts, false, "trace contexts operations")
 
 // heap.cc
 DEFINE_bool(gc_greedy, false, "perform GC prior to some allocations")
 DEFINE_bool(gc_verbose, false, "print stuff during garbage collection")
 DEFINE_bool(heap_stats, false, "report heap statistics before and after GC")
 DEFINE_bool(code_stats, false, "report code statistics after GC")
 DEFINE_bool(verify_heap, false, "verify heap pointers before and after GC")
+DEFINE_bool(verify_global_context_separation, false,
+            "verify that code holds on to at most one global context after GC")
 DEFINE_bool(print_handles, false, "report handles after GC")
 DEFINE_bool(print_global_handles, false, "report global handles after GC")
 
 // ic.cc
 DEFINE_bool(trace_ic, false, "trace inline cache state transitions")
 
 // interface.cc
 DEFINE_bool(print_interfaces, false, "print interfaces")
 DEFINE_bool(print_interface_details, false, "print interface inference details")
 DEFINE_int(print_interface_depth, 5, "depth for printing interfaces")
@@ skipping 114 matching lines @@
 #undef DEFINE_bool
 #undef DEFINE_int
 #undef DEFINE_string
 #undef DEFINE_implication
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META
 #undef FLAG_MODE_DEFINE_IMPLICATIONS