ctf: translate annotation DIEs to internal ctf

ctf: translate annotation DIEs to internal ctf

Translate DW_TAG_GNU_annotation DIEs created for C attributes
btf_decl_tag and btf_type_tag into an in-memory representation in the
CTF/BTF container.  They will be output in BTF as BTF_KIND_DECL_TAG and
BTF_KIND_TYPE_TAG records.

The new CTF kinds used to represent these annotations, CTF_K_DECL_TAG
and CTF_K_TYPE_TAG, are expected to be formalized in the next version of
the CTF specification.  For now they only exist in memory as a
translation step to BTF, and are not emitted when generating CTF
information.

gcc/
	* ctfc.cc (ctf_dtu_d_union_selector): Handle CTF_K_DECL_TAG and
	CTF_K_TYPE_TAG.
	(ctf_add_type_tag, ctf_add_decl_tag): New.
	(ctf_add_variable): Return the new ctf_dvdef_ref rather than zero.
	(new_ctf_container): Initialize new members.
	(ctfc_delete_container): Deallocate new members.
	* ctfc.h (ctf_dvdef, ctf_dvdef_t, ctf_dvdef_ref): Move forward
	declarations earlier in file.
	(ctf_decl_tag_t): New typedef.
	(ctf_dtdef): Add ctf_decl_tag_t member to dtd_u union.
	(ctf_dtu_d_union_enum): Add new CTF_DTU_D_TAG enumerator.
	(ctf_container): Add ctfc_tags vector and ctfc_type_tags_map hash_map
	members.
	(ctf_add_type_tag, ctf_add_decl_tag): New function protos.
	(ctf_add_variable): Change prototype return type to ctf_dvdef_ref.
	* dwarf2ctf.cc (gen_ctf_type_tags, gen_ctf_decl_tags)
	(gen_ctf_decl_tags_for_var): New static functions.
	(gen_ctf_pointer_type): Handle type tags.
	(gen_ctf_sou_type): Handle decl tags.
	(gen_ctf_function_type): Likewise.
	(gen_ctf_variable): Likewise.
	(gen_ctf_function): Likewise.
	(gen_ctf_type): Handle TAG_GNU_annotation DIEs.

gcc/testsuite/
	* gcc.dg/debug/ctf/ctf-decl-tag-1.c: New test.
	* gcc.dg/debug/ctf/ctf-type-tag-1.c: New test.

include/
	* ctf.h (CTF_K_DECL_TAG, CTF_K_TYPE_TAG): New defines.