glsl: relax input->output validation for SSO programs

glsl: relax input->output validation for SSO programs

Commit 18004c3 introduced more restrictive validation to linker
between inputs and outputs. This patch skips the additional check
for programs that utilize GL_ARB_separate_shader_objects, there
inputs and outputs might not make exact match during linking but
only when constructing the final pipeline.

This made some of the GL_ARB_program_interface_query tests shaders
fail to link, these tests can be used to verify the change.

Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>