libctf: remove static/dynamic name lookup distinction

libctf internally maintains a set of hash tables for type name lookups,
one for each valid C type namespace (struct, union, enum, and everything
else).

Or, rather, it maintains *two* sets of hash tables: one, a ctf_hash *,
is meant for lookups in ctf_(buf)open()ed dicts with fixed content; the
other, a ctf_dynhash *, is meant for lookups in ctf_create()d dicts.

This distinction was somewhat valuable in the far pre-binutils past when
two different hashtable implementations were used (one expanding, the
other fixed-size), but those days are long gone: the hash table
implementations are almost identical, both wrappers around the libiberty
hashtab. The ctf_dynhash has many more capabilities than the ctf_hash
(iteration, deletion, etc etc) and has no downsides other than starting
at a fixed, arbitrary small size.

That limitation is easy to lift (via a new ctf_dynhash_create_sized()),
following which we can throw away nearly all the ctf_hash
implementation, and all the code to choose between readable and writable
hashtabs; the few convenience functions that are still useful (for
insertion of name -> type mappings) can also be generalized a bit so
that the extra string verification they do is potentially available to
other string lookups as well.

(libctf still has two hashtable implementations, ctf_dynhash, above,
and ctf_dynset, which is a key-only hashtab that can avoid a great many
malloc()s, used for high-volume applications in the deduplicator.)

libctf/

	* ctf-create.c (ctf_create): Eliminate ctn_writable.
	(ctf_dtd_insert): Likewise.
	(ctf_dtd_delete): Likewise.
	(ctf_rollback): Likewise.
	(ctf_name_table): Eliminate ctf_names_t.
	* ctf-hash.c (ctf_dynhash_create): Comment update.
        Reimplement in terms of...
	(ctf_dynhash_create_sized): ... this new function.
	(ctf_hash_create): Remove.
	(ctf_hash_size): Remove.
	(ctf_hash_define_type): Remove.
	(ctf_hash_destroy): Remove.
	(ctf_hash_lookup_type): Rename to...
	(ctf_dynhash_lookup_type): ... this.
	(ctf_hash_insert_type): Rename to...
	(ctf_dynhash_insert_type): ... this, moving validation to...
	* ctf-string.c (ctf_strptr_validate): ... this new function.
	* ctf-impl.h (struct ctf_names): Extirpate.
	(struct ctf_lookup.ctl_hash): Now a ctf_dynhash_t.
	(struct ctf_dict): All ctf_names_t fields are now ctf_dynhash_t.
	(ctf_name_table): Now returns a ctf_dynhash_t.
	(ctf_lookup_by_rawhash): Remove.
	(ctf_hash_create): Likewise.
	(ctf_hash_insert_type): Likewise.
	(ctf_hash_define_type): Likewise.
	(ctf_hash_lookup_type): Likewise.
	(ctf_hash_size): Likewise.
	(ctf_hash_destroy): Likewise.
	(ctf_dynhash_create_sized): New.
	(ctf_dynhash_insert_type): New.
	(ctf_dynhash_lookup_type): New.
	(ctf_strptr_validate): New.
	* ctf-lookup.c (ctf_lookup_by_name_internal): Adapt.
	* ctf-open.c (init_types): Adapt.
	(ctf_set_ctl_hashes): Adapt.
	(ctf_dict_close): Adapt.
	* ctf-serialize.c (ctf_serialize): Adapt.
	* ctf-types.c (ctf_lookup_by_rawhash): Remove.

libctf/ctf-types.c

@@ -635,22 +635,8 @@ ctf_get_dict (ctf_dict_t *fp, ctf_id_t type)
 
 ctf_id_t ctf_lookup_by_rawname (ctf_dict_t *fp, int kind, const char *name)
 {
-  return ctf_lookup_by_rawhash (fp, ctf_name_table (fp, kind), name);
-}
-
-/* Look up a name in the given name table, in the appropriate hash given the
-   readability state of the dictionary.  The name is a raw, undecorated
-   identifier.  */
-
-ctf_id_t ctf_lookup_by_rawhash (ctf_dict_t *fp, ctf_names_t *np, const char *name)
-{
-  ctf_id_t id;
-
-  if (fp->ctf_flags & LCTF_RDWR)
-    id = (ctf_id_t) (uintptr_t) ctf_dynhash_lookup (np->ctn_writable, name);
-  else
-    id = ctf_hash_lookup_type (np->ctn_readonly, fp, name);
-  return id;
+  return (ctf_id_t) (uintptr_t)
+    ctf_dynhash_lookup (ctf_name_table (fp, kind), name);
 }
 
 /* Lookup the given type ID and return its name as a new dynamically-allocated