meson: Do hard build error for some MSVC warnings

... and handle C4013 warning (default warning level is 3) for
"implicit function decl." warnings to be caught.
25 jobs for !1006 with msvc-warnings in 21 seconds (queued for 22 seconds)
detached
Status Name Job ID Coverage
  Build Docker
passed fedora amd64 docker #14265445

00:00:17

passed gst-indent amd64 docker #14265446

00:00:17

passed windows amd64 docker #14265447
windows shell 1809

00:00:16

 
  Preparation
passed check allow-edit #14265449

00:00:10

manual gst indent #14265448
manual
 
  Build
created build clang fedora x86_64 #14265453
created build documentation #14265457
created build msys2 #14265456
docker windows 1809 allowed to fail manual
created build nodebug fedora x86_64 #14265450
created build static fedora x86_64 #14265451
created build static nodebug fedora x86_64 #14265452
created build vs2017 amd64 #14265454
docker windows 1809
created build vs2017 x86 #14265455
docker windows 1809
created cerbero trigger #14265458
 
  Test
created check fedora #14265459
gstreamer
created integration testsuites fedora 1/4 #14265460
gstreamer
created integration testsuites fedora 2/4 #14265461
gstreamer
created integration testsuites fedora 3/4 #14265462
gstreamer
created integration testsuites fedora 4/4 #14265463
gstreamer
created valgrind bad #14265468
gstreamer
created valgrind base #14265465
gstreamer
created valgrind core #14265464
gstreamer
created valgrind ges #14265469
gstreamer
created valgrind good #14265466
gstreamer
created valgrind ugly #14265467
gstreamer