Add v8_os_page_size flag for cross compilation

src/flag-definitions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file defines all of the flags.  It is separated into different section,
 // for Debug, Release, Logging and Profiling, etc.  To add a new flag, find the
 // correct section, and use one of the DEFINE_ macros, without a trailing ';'.
 //
 // This include does not have a guard, because it is a template-style include,
 // which can be included multiple times in different modes.  It expects to have
@@ skipping 1001 matching lines @@
 
 // runtime.cc
 DEFINE_BOOL(trace_lazy, false, "trace lazy compilation")
 
 // spaces.cc
 DEFINE_BOOL(collect_heap_spill_statistics, false,
             "report heap spill statistics along with heap_stats "
             "(requires heap_stats)")
 DEFINE_BOOL(trace_live_bytes, false,
             "trace incrementing and resetting of live bytes")
-
 DEFINE_BOOL(trace_isolates, false, "trace isolate state changes")
+DEFINE_INT(target_os_page_size, 0,
+           "override os page size when generating snapshot")
 
 // Regexp
 DEFINE_BOOL(regexp_possessive_quantifier, false,
             "enable possessive quantifier syntax for testing")
 DEFINE_BOOL(trace_regexp_bytecodes, false, "trace regexp bytecode execution")
 DEFINE_BOOL(trace_regexp_assembler, false,
             "trace regexp macro assembler calls.")
 DEFINE_BOOL(trace_regexp_parser, false, "trace regexp parsing")
 
 // Debugger
@@ skipping 179 matching lines @@
 #undef DEFINE_ALIAS_FLOAT
 #undef DEFINE_ALIAS_ARGS
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META
 #undef FLAG_MODE_DEFINE_IMPLICATIONS
 
 #undef COMMA