mesa/glsl: move BlendSupport bitfield to gl_program

This will let us to make _CurrentFragmentProgram a gl_program pointer
allowing for simpilifications to be made.

We also need to add a field to gl_shader to hold it during parsing.

In gl_program we put it inside a union in anticipation of moving
more fields here that can be only fs or vertex stage fields.

Reviewed-by: Eric Anholt <eric@anholt.net>

src/compiler/glsl/glsl_parser_extras.cpp

@@ -1818,7 +1818,7 @@ set_shader_inout_layout(struct gl_shader *shader,
       shader->info.EarlyFragmentTests = state->fs_early_fragment_tests;
       shader->info.InnerCoverage = state->fs_inner_coverage;
       shader->info.PostDepthCoverage = state->fs_post_depth_coverage;
-      shader->info.BlendSupport = state->fs_blend_support;
+      shader->BlendSupport = state->fs_blend_support;
       break;
 
    default:

src/compiler/glsl/linker.cpp

@@ -1829,7 +1829,6 @@ link_fs_inout_layout_qualifiers(struct gl_shader_program *prog,
    linked_shader->info.uses_gl_fragcoord = false;
    linked_shader->info.origin_upper_left = false;
    linked_shader->info.pixel_center_integer = false;
-   linked_shader->info.BlendSupport = 0;
 
    if (linked_shader->Stage != MESA_SHADER_FRAGMENT ||
        (prog->data->Version < 150 &&
@@ -1894,7 +1893,7 @@ link_fs_inout_layout_qualifiers(struct gl_shader_program *prog,
       linked_shader->Program->info.fs.post_depth_coverage |=
          shader->info.PostDepthCoverage;
 
-      linked_shader->info.BlendSupport |= shader->info.BlendSupport;
+      linked_shader->Program->sh.fs.BlendSupport |= shader->BlendSupport;
    }
 }
 

src/compiler/glsl/lower_blend_equation_advanced.cpp

@@ -463,7 +463,7 @@ get_main(gl_linked_shader *sh)
 bool
 lower_blend_equation_advanced(struct gl_linked_shader *sh)
 {
-   if (sh->info.BlendSupport == 0)
+   if (sh->Program->sh.fs.BlendSupport == 0)
       return false;
 
    /* Lower early returns in main() so there's a single exit point
@@ -547,7 +547,8 @@ lower_blend_equation_advanced(struct gl_linked_shader *sh)
    ir_factory f(&main->body, mem_ctx);
 
    ir_variable *result_dest =
-      calc_blend_result(f, mode, fb, blend_source, sh->info.BlendSupport);
+      calc_blend_result(f, mode, fb, blend_source,
+                        sh->Program->sh.fs.BlendSupport);
 
    /* Copy the result back to the original values.  It would be simpler
     * to demote the program's output variables, and create a new vec4