m4: update to 1.4.19

update 1.4.18 (2017-01-01) to 1.4.19 (2021-05-28)
ann: https://lists.gnu.org/archive/html/m4-announce/2021-05/msg00002.html

Includes upstreamed patch for fix-compilation-with-glibc-2.28.patch

NEWS
* Noteworthy changes in release 1.4.19 (2021-05-28) [stable]
** A number of portability improvements inherited from gnulib, including
   the ability to perform stack overflow detection on more platforms
   without linking to GNU libsigsegv.

* Noteworthy changes in release 1.4.18d (2021-05-11) [beta]
** A number of portability improvements inherited from gnulib.

* Noteworthy changes in release 1.4.18b (2021-05-07) [beta]
** The symbol hash table now defaults to 65537 buckets instead of 509, as
   modern systems have enough memory to benefit from fewer hash collisions
   by default.
** Introduce the use of gettext, with the immediate benefit of nicer
   UTF-8 author names.  Over time, more translations of program messages
   will become available.
** A number of portability improvements inherited from gnulib.

packages/devel/m4/package.mk

@@ -2,8 +2,8 @@
 # Copyright (C) 2009-2016 Stephan Raue (stephan@openelec.tv)
 
 PKG_NAME="m4"
-PKG_VERSION="1.4.18"
-PKG_SHA256="6640d76b043bc658139c8903e293d5978309bf0f408107146505eca701e67cf6"
+PKG_VERSION="1.4.19"
+PKG_SHA256="b306a91c0fd93bc4280cfc2e98cb7ab3981ff75a187bea3293811f452c89a8c8"
 PKG_LICENSE="GPL"
 PKG_SITE="http://www.gnu.org/software/m4/"
 PKG_URL="http://ftpmirror.gnu.org/m4/${PKG_NAME}-${PKG_VERSION}.tar.bz2"