Non-reentrant code generated by C compiler

[gwyn at BRL-VLD.ARPA]

From:      Doug Gwyn (VLD/VMB) <gwyn at BRL-VLD.ARPA>

If you start worrying about staying compatible with 6th Edition C,
you have REAL portability problems.  6th Edition UNIX did not have
the current stdio, or any of the portability features put into C
for the 7th Edition (typecasts, for example).  It is really asking
too much to insist on 6th-Edition compatible C code.