libctf: exclude always-emitted Solaris symbols from the symtypetab

libctf: exclude always-emitted Solaris symbols from the symtypetab

If we're skipping _BEGIN_ and _END_ we should certainly skip all the other
ABI-required always-emitted symbols given in ld/emultempl/solaris2*em as
well.  (This fixes a couple of diagnostics tests, but that's just because
the tests are quite sensitive to CTF section sizes, and introducing any
symtypetab entries for those tests perturbs those.)

Some of these are usually STT_NOTYPE, but not always: if programs already
emitted the symbol they might end up with any type, in particular
STT_OBJECT, and appear in the symtypetabs.

[nca: added commit log, added more symbols]

libctf/
	PR libctf/33162
	* ctf-serialize.c (ctf_symtab_skippable): Skip
	more always-emitted Solaris symbols.