A few more functions are not pure

Assuming ATTRIBUTE_PURE means that the function must return,
a few more functions that should not be declared with ATTRIBUTE_PURE.
The GCC manual (and even the C23 standard, with [[reproducible]])
is not clear about this, and it’s better to be safe.
* src/bignum.h (mpz_get_d_rounded):
* src/lisp.h (bignum_to_double):
No longer pure, as it does not return if memory is exhausted.
* src/fns.c (Fproper_list_p): No longer pure, as it does not
return if the user quits.
* src/gnutls.c (Fgnutls_errorp): No longer pure, as it does not
return if it runs into an eassert failure in XSYMBOL_WITH_POS via EQ.
* src/lisp.h (bignum_to_intmax, bignum_to_uintmax, bignum_bufsize):
No longer pure, as it does not return if it runs into an
eassert failure in XBIGNUM via xbignum_val.

1 files changed, 1 insertions, 2 deletions

diff --git a/src/gnutls.c b/src/gnutls.c
index 247cc7ff3fe..31827280b48 100644
--- a/src/gnutls.c
+++ b/src/gnutls.c
@@ -1002,8 +1002,7 @@ See also `gnutls-boot'.  */)
 DEFUN ("gnutls-errorp", Fgnutls_errorp, Sgnutls_errorp, 1, 1, 0,
        doc: /* Return t if ERROR indicates a GnuTLS problem.
 ERROR is an integer or a symbol with an integer `gnutls-code' property.
-usage: (gnutls-errorp ERROR)  */
-       attributes: pure)
+usage: (gnutls-errorp ERROR)  */)
   (Lisp_Object err)
 {
   if (EQ (err, Qt)