isnan: Fix porting problem to Solaris 10 with bundled gcc.

Without this fix, the command to link temacs failed due to an
undefined symbol __builtin_isnan.  This is because
/usr/include/iso/math_c99.h #defines isnan(x) to
__builtin_isnan(x), but the bundled gcc, which identifies itself
as gcc 3.4.3 (csl-sol210-3_4-branch+sol_rpath), does not have
a __builtin_isnan.
* configure.in (isnan): Remove now-unnecessary check.
* src/floatfns.c (isnan): #undef, and then #define to a clone of
what's in data.c.
(Fisnan): Always define, since it's always available now.
(syms_of_floatfns): Always define isnan at the Lisp level.

1 files changed, 4 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index f33d61ef9f1..437c6dba2f1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2011-09-06  Paul Eggert  <eggert@cs.ucla.edu>
 
+        * configure.in (isnan): Remove now-unnecessary check.
+
+2011-09-06  Paul Eggert  <eggert@cs.ucla.edu>
+
         Merge from gnulib, using build-aux to remove clutter (Bug#9169).
         This is to fix the following problems:
          . On FreeBSD 6.4, HP-UX 11.31, and Solaris 9, and when Emacs is