Patch: add pa2.0 media instructions

[Jeffrey A Law]

  In message <199908052124.OAA28480@cygnus.com>you write:
  > Here's some more pa2.0 instructions and test cases.  This covers the
  > halfword multimedia instructions.
  > 
  > ChangeLog entry:
  > 
  > Thu Aug  5 17:18:11 EDT 1999  Jerry Quinn <jquinn@nortelnetworks.com>
  > 
  >     * include/opcode/hppa.h (pa_opcodes):  Add pa2.0 instructions hadd, hsh
  > l,
  >     hshr, hsub, mixh, mixw, permh.
  >     * gas/tc-hppa.c (pa_ip):  Add completer codes 'a', 'ch', 'cH', 'cS', an
  > d
  >     'c*'.
  >     * opcodes/hppa-dis.c (signed_unsigned_names,mix_half_names,
  >     saturation_names):  New.
  >     (print_insn_hppa): Add completer codes 'a', 'ch', 'cH', 'cS', and 'c*'.
  > 
  >     * gas/testsuite/gas/hppa/basic/basic.exp:
  >     * gas/testsuite/gas/hppa/basic/media.s:  Add test cases for new
  >     instructions.
Thanks.  Installed.

I'm not 100% sure the mask for hshr/hshl is correct.  I'll double check in
a few minutes and declare it OK or check in a fix.

jeff