* configure.in (*-*-sunos*): Use trailing * to match all

* configure.in (*-*-sunos*):  Use trailing * to match all
sub-variants of SunOS, e.g. sunos4* to match sunos4.1.1.
(sparc-*-sunos3):  Remove host & target.  Sunos3 never shipped
in production on Sun-4.
({a29k,i[34]86,i960}-*-elf):  Add targets, equivalent to coff.
(m68k-*-{aout,coff,elf}):  Add targets, w/new config and tm files.
(sparc-*-{aout,coff,elf}):  Add targets, w/new config and tm files.

* tm-68k-un.h, tm-68k-noun.h, tm-spc-un.h, tm-spc-noun.h:  New
target definitions for embedded with and without underlines on
identifiers.  FIXME -- this ought to be known by BFD instead.

* tm-sparc.h, tm-sun2.h, tm-sun3.h:  Delete NAMES_HAVE_UNDERSCORE:
not a parameter of the CPU, but of the development environment.
* tm-es1800.h, tm-sunos.h, tm-vx68.h:  Add NAMES_HAVE_UNDERSCORE.