m4 1.4.20 on alpha and hppa

Hello.

I updated the Debian package for m4 and now it does not build ok in
alpha and hppa (Linux in both cases).

This is what happens in alpha:

-------------------------------------------------------------------------
gcc -DEXEEXT=\"\" -DEXEEXT=\"\" -I. -I../lib  -DIN_M4_GNULIB_TESTS=1 -I. -I. -I.. -I./.. -I../lib -I./../lib -Wdate-time -D_FORTIFY_SOURCE=2 -mieee  -Wno-error -Wno-cast-qual -Wno-conversion -Wno-float-equal -Wno-sign-compare -Wno-undef -Wno-unused-function -Wno-unused-parameter -Wno-float-conversion -Wimplicit-fallthrough -Wno-pedantic -Wno-sign-conversion -Wno-type-limits -Wno-unused-const-variable -Wno-unsuffixed-float-constants -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/m4-1.4.20=. -c -o test-sys_stat-h.o test-sys_stat-h.c
In file included from test-sys_stat-h.c:19:
../lib/config.h:4125:25: error: static assertion failed
 4125 |   #define static_assert _Static_assert
      |                         ^~~~~~~~~~~~~~
test-sys_stat-h.c:343:1: note: in expansion of macro 'static_assert'
  343 | static_assert (TYPE_SIGNED (blksize_t));
      | ^~~~~~~~~~~~~
../lib/config.h:4125:25: error: static assertion failed
 4125 |   #define static_assert _Static_assert
      |                         ^~~~~~~~~~~~~~
test-sys_stat-h.c:348:1: note: in expansion of macro 'static_assert'
  348 | static_assert (TYPE_SIGNED (blkcnt_t));
      | ^~~~~~~~~~~~~
-------------------------------------------------------------------------

and this is what happens in hppa:

-------------------------------------------------------------------------
Checking ./stackovf.test
Stack soft limit set to 8192K
Failure - m4 aborted unexpectedly
Output from m4:
m4: internal error detected; please report this bug to <[email protected]>: Segmentation fault

Skipped checks were:
  ./127.changeword ./128.changeword ./129.changeword ./130.changeword ./131.changeword ./132.changeword ./133.changeword
Failed checks were:
  ./stackovf.test
make[4]: *** [Makefile:2574: check-local] Error 1
-------------------------------------------------------------------------

It might be worth to mention that this used to work five months ago
with 1.4.19, so this is a regression.

Full build logs available here, just click on the red "Build-Attempted":

https://buildd.debian.org/status/package.php?p=m4

Thanks.