Build failure since update to mingw-w64 8.0.0

[Rene Kita]

Since commit "151f5502 mingw-w64: update to 8.0.0" building mxe fails for
me when building check.


  [build]       check                  i686-w64-mingw32.static

Failed to build package check for target i686-w64-mingw32.static!
------------------------------------------------------------
Make[3]: *** [Makefile:321: snprintf.lo] Error 1
Make[3]: Leaving directory 
'/home/kt/mxe/tmp-check-i686-w64-mingw32.static/check-0.10.0/lib'


This is after a fresh clone:
  git clone https://github.com/mxe/mxe.git
  cd mxe
  make -j8 check


Relevant part from log/check_i686-w64-mingw32.static:


  uname -a
  Linux t480 5.4.0-58-generic #64-Ubuntu SMP Wed Dec 9 08:16:25 UTC 2020 x86_64 
x86_64 x86_64 GNU/Linux
  git log --pretty=tformat:"%H - %s [%ar] [%d]" -1
  2d95bd76abfbba76af6f856c7fbac276f8808a48 - Update packages.json & 
build-matrix.html [35 hours ago] [ (HEAD -> mas
  ter, origin/master, origin/HEAD)]
  lsb_release -a 2>/dev/null || sw_vers 2>/dev/null || true
  Distributor ID: Ubuntu
  Description:    Ubuntu 20.04.1 LTS
  Release:        20.04
  Codename:       focal
  autoconf --version 2>/dev/null | head -1
  autoconf (GNU Autoconf) 2.69
  automake --version 2>/dev/null | head -1
  automake (GNU automake) 1.16.1
  gcc --version
  gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0

  [...]

  snprintf.c:529:1: error: redefinition of 'rpl_vsnprintf'
   rpl_vsnprintf(char *str, size_t size, const char *format, va_list args)
   ^
  compilation terminated due to -Wfatal-errors.


The complete log is attached.

Please let me know if I need to provide more information.

check_i686-w64-mingw32.static
Description: Text document