Add C++ attribute abi_tag and -Wabi-tag option.
gcc/
* attribs.c (lookup_attribute_spec): Handle getting a TREE_LIST.
gcc/c-family/
* c.opt (Wabi-tag): New.
gcc/cp/
* tree.c (cxx_attribute_table): Add abi_tag attribute.
(check_abi_tag_redeclaration, handle_abi_tag_attribute): New.
* class.c (find_abi_tags_r, check_abi_tags): New.
(check_bases, check_field_decl): Call check_abi_tags.
* decl.c (redeclaration_error_message): Call
check_abi_tag_redeclaration.
* mangle.c (tree_string_cmp, write_abi_tags): New.
(write_unqualified_name): Call write_abi_tags.
include/
* demangle.h (enum demangle_component_type): Add
DEMANGLE_COMPONENT_TAGGED_NAME.
libiberty/
* cp-demangle.c (d_dump): Handle DEMANGLE_COMPONENT_TAGGED_NAME.
(d_make_comp, d_find_pack, d_print_comp): Likewise.
(d_abi_tags): New.
(d_name): Call it.
From-SVN: r193367
7dbb85a793