glsl: use bool literals instead of integers

Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12674>

src/compiler/glsl/ast_to_hir.cpp

@@ -3970,9 +3970,9 @@ apply_layout_qualifier_to_variable(const struct ast_type_qualifier *qual,
          _mesa_glsl_error(loc, state, "gl_Layer redeclaration with "
                           "different viewport_relative setting than earlier");
       }
-      state->redeclares_gl_layer = 1;
+      state->redeclares_gl_layer = true;
       if (qual->flags.q.viewport_relative) {
-         state->layer_viewport_relative = 1;
+         state->layer_viewport_relative = true;
       }
    } else if (qual->flags.q.viewport_relative) {
       _mesa_glsl_error(loc, state,

src/compiler/glsl/link_varyings.cpp

@@ -2173,7 +2173,7 @@ varying_matches::store_locations() const
    /* Check is location needs to be packed with lower_packed_varyings() or if
     * we can just use ARB_enhanced_layouts packing.
     */
-   bool pack_loc[MAX_VARYINGS_INCL_PATCH] = { 0 };
+   bool pack_loc[MAX_VARYINGS_INCL_PATCH] = {};
    const glsl_type *loc_type[MAX_VARYINGS_INCL_PATCH][4] = { {NULL, NULL} };
 
    for (unsigned i = 0; i < this->num_matches; i++) {

src/compiler/glsl/opt_dead_builtin_varyings.cpp

@@ -527,7 +527,7 @@ lower_fragdata_array(struct gl_linked_shader *shader)
    varying_info_visitor info(ir_var_shader_out, true);
    info.get(shader->ir, 0, NULL);
 
-   replace_varyings_visitor(shader, &info, 0, 0, 0);
+   replace_varyings_visitor(shader, &info, 0, 0, false);
 }