drirc: Add allow_glsl_builtin_variable_redeclaration for Dying Light and Dead Island...

drirc: Add allow_glsl_builtin_variable_redeclaration for Dying Light and Dead Island Definitive Edition

This fixes the long-standing problem with Dying Light where the game would
produce a black screen when running under Mesa. This happened because the
game's vertex shaders redeclare gl_VertexID, which is a GLSL builtin.
Mesa's GLSL compiler is a little more strict than others, and would not
compile them:

    error: `gl_VertexID' redeclared

The allow_glsl_builtin_variable_redeclaration directive allows the shaders
to compile and the game to render. The game also requires OpenGL 4.4+ (GLSL
440), but does not request it explicitly. It must be forced with an
override, such as MESA_GL_VERSION_OVERRIDE=4.5 and
MESA_GLSL_VERSION_OVERRIDE=450. A compatibility context is *not* required
and forcing one with 4.5COMPAT or allow_higher_compat_version results in
graphical artifacts.

Dead Island Definitive Edition is another Techland port on the same engine
with the same problems, so we set the
allow_glsl_builtin_variable_redeclaration option for that game as well.

v2 (Samuel Pitoiset):
    - Rename allow_glsl_builtin_redeclaration ->
      allow_glsl_builtin_variable_redeclaration

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96449
Signed-off-by: John Brooks <john@fastquake.com>
Reviewed-by: Edward O'Callaghan <funfunctor@folklore1984.net>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>