patch to support Sun C 5.8's implementation of C99

[Paul Eggert]

At some point (I don't know exactly when) Sun seems to have added a
compiler option to support C99 without messing up and mistakenly
claiming that older Solaris libraries support C99.  So I installed
this patch into Autoconf:

2006-12-06  Paul Eggert  <address@hidden>

        * lib/autoconf/c.m4 (_AC_PROG_CC_C89): Also try -xc99=all, for Sun
        C 5.8 on Solaris 10.  Using -xc99=all rather than -xc99 bypasses
        the buggy -xc99 option of Forte Developer 7 C on Solaris 9.

--- lib/autoconf/c.m4   1 Dec 2006 19:21:03 -0000       1.241
+++ lib/autoconf/c.m4   7 Dec 2006 06:39:16 -0000
@@ -1278,11 +1278,11 @@
 dnl AIX                -qlanglvl=extc99 (unused restrictive mode: 
-qlanglvl=stdc99)
 dnl Intel ICC  -c99
 dnl IRIX       -c99
-dnl Solaris    (unused because it causes the compiler to assume C99 semantics 
for
-dnl            library functions, and this is invalid before Solaris 10: -xc99)
+dnl Solaris    -xc99=all (Forte Developer 7 C mishandles -xc99 on Solaris 9,
+dnl            as it incorrectly assumes C99 semantics for library functions)
 dnl Tru64      -c99
 dnl with extended modes being tried first.
-[[-std=gnu99 -c99 -qlanglvl=extc99]], [$1], [$2])[]dnl
+[[-std=gnu99 -c99 -xc99=all -qlanglvl=extc99]], [$1], [$2])[]dnl
 ])# _AC_PROG_CC_C99