util: Allow STATIC_ASSERT() everywhere

Remove -Werror=vla from c_msvc_compat_args so we can use STATIC_ASSERT()
in core code.  We have a CI job for this.

(And arguably we could probably just drop c_msvc_compat_args entirely.)

Signed-off-by: Rob Clark <robdclark@chromium.org>
Acked-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7941>

scons/gallium.py

@@ -86,7 +86,6 @@ def install_shared_library(env, sources, version = ()):
 def msvc2013_compat(env):
     if env['gcc']:
         env.Append(CCFLAGS = [
-            '-Werror=vla',
             '-Werror=pointer-arith',
         ])