[Linux] Patch LogSharedLibraryAddresses to work correctly on Android.

[Linux] Patch LogSharedLibraryAddresses to work correctly on Android.

On 'usual' Linux systems in '/proc/self/maps' we encounter two entries
per library: one has 'rw-p' attrs and the other has 'r-xp'. While on
Android, I see 'rwxp' and 'r-xp' (both entries are marked executable.)
So I've added an explicit check for non-writability to leave only a
single record in the log file.

Committed: http://code.google.com/p/v8/source/detail?r=4018

[Søren Thygesen Gjesse, 2010-03-04 07:59:27]

LGTM