[samba4] lex.c AIX fix was reverted by r19604

[Chris Cowan]

I've been compiling recent versions of samba4 on AIX and ran into this
snag.   It appears that r19604 reverted this change by Tridge in
heimdal/lib/asn1/lex.c and heimdal/lib/com_err/lex.c (perhaps this should
be forwarded to the heimdal team?):

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r18322 | tridge | 2006-09-10 05:02:10 -0500 (Sun, 10 Sep 2006) | 5 lines


fixed a compilation problem on AIX caused by lex not putting config.h
first. That leads to a conflicting define for lseek() due to
_LARGE_FILES being defined after standards headers are included

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Regards,
CC