main: legal_get_tex_level_parameter_target now handles GL_TEXTURE_CUBE_MAP.
main: legal_get_tex_level_parameter_target now handles GL_TEXTURE_CUBE_MAP.

ARB_DIRECT_STATE_ACCESS functions allow an effective target of
GL_TEXTURE_CUBE_MAP.

Reviewed-by: Anuj Phogat <e2026475996c48f0b97fd37e84129b3912980428@gmail.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler