PR debug/29436, c/32326

PR debug/29436, c/32326

        PR debug/29436, c/32326
        * tree.c (build_type_attribute_qual_variant): Refuse to make
        a distinct copy of a struct/enum type.  Use build_distinct_type_copy.
        * doc/extend.texi (Type Attributes): Don't encourage people to add
        attributes to struct/enum types in a typedef.  Fix
        transparent_union example.

        * tree-inline.c (remap_type_1): Remove code that's redundant with
        remap_type.
        (build_duplicate_type): Set id.copy_decl.
        * c-common.c (handle_transparent_union_attribute): Simplify logic.

From-SVN: r130297