Add v8_os_page_size flag for cross compilation

src/flag-definitions.h

Index: src/flag-definitions.h
diff --git a/src/flag-definitions.h b/src/flag-definitions.h
index 41e0c43e0650edb83c1e9af836ef3022193d4507..8a0594ecc7d18645efabb427769c6ba3868f0415 100644
--- a/src/flag-definitions.h
+++ b/src/flag-definitions.h
@@ -767,6 +767,9 @@ DEFINE_BOOL(scavenge_reclaim_unmodified_objects, true,
 DEFINE_INT(heap_growing_percent, 0,
            "specifies heap growing factor as (1 + heap_growing_percent/100)")
 
+// spaces.cc
+DEFINE_INT(v8_os_page_size, 0, "override os page size when generating snapshot")

[Michael Lippautz, 2016/11/14 16:04:08]

"override OS page size (in KBytes)"

I think kbytes makes sense, leave it in bytes if you disagree.

+
 // execution.cc, messages.cc
 DEFINE_BOOL(clear_exceptions_on_js_entry, false,
             "clear pending exceptions when entering JavaScript")
@@ -1019,7 +1022,6 @@ DEFINE_BOOL(collect_heap_spill_statistics, false,
             "(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")
 
 // Regexp