Substitute a <ieee754.h> on hosts lacking it

* .gitignore: Add lib/ieee754.h.
* admin/merge-gnulib (GNULIB_MODULES): Add ieee754-h.
* configure.ac: Remove ieee754.h check, as Gnulib now does that.
* etc/NEWS: Mention this.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lib/ieee754.in.h, m4/ieee754-h.m4: New files, from Gnulib.
* src/lisp.h (IEEE_FLOATING_POINT): Now a macro so that it
can be used in #if.
* src/lread.c, src/print.c: Include <ieee754.h> if
IEEE_FLOATING_POINT, not if HAVE_IEEE754_H.
* src/lread.c (string_to_number):
* src/print.c (float_to_string):
Process NaNs only on IEEE hosts, and assume <ieee754.h>
in that case.

1 files changed, 3 insertions, 3 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 9e7a765dc61..6c79a46f243 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -880,9 +880,9 @@ Formerly, some of these functions ignored signs and significands of
 NaNs.  Now, all these functions treat NaN signs and significands as
 significant.  For example, (eql 0.0e+NaN -0.0e+NaN) now returns nil
 because the two NaNs have different signs; formerly it returned t.
-Also, on platforms that have <ieee754.h> Emacs now reads and prints
-NaN significands; e.g., if X is a NaN, (format "%s" X) now returns
-"0.0e+NaN", "1.0e+NaN", etc., depending on X's significand.
+Also, Emacs now reads and prints NaN significands; e.g., if X is a
+NaN, (format "%s" X) now returns "0.0e+NaN", "1.0e+NaN", etc.,
+depending on X's significand.
 
 +++
 ** The function 'make-string' accepts an additional optional argument.