Fix code in elf_symtab_read which attempts to read the standard ELF

Fix code in elf_symtab_read which attempts to read the standard ELF
symbol table and add symbol information to the misc function vector.
This allows minimum functionality with non -g compiled code, and is
vital for use with shared libraries (non of which are currently
compiled with -g).

Note to anyone doing any SVR4/gdb work.  This bug was introduced into
gdb just prior to the gdb 4.4 release, thus any versions currently
in the field will have broken shared library support since no symbol
information at all will be available for the shared library.  This
fix, along with one about to go into bfd's elf.c should fix that
problem.