Bug 385412 - s390x: new non-vector z13 instructions not implemented

Bug 385412 - s390x: new non-vector z13 instructions not implemented

Apart from instructions with vector operands, Valgrind does not implement the
additional z/Architecture instructions introduced with z13.

These are:
- load and zero rightmost byte (LZRF, LZRG);
- load logical and zero rightmost byte (LLZRGF);
- load halfword high immediate on condition (LOCHHI);
- load halfword immediate on condition (LOCHI, LOCGHI);
- load high on condition (LOCFHR, LOCFH);
- store high on condition (STOCFH);
- perform pseudorandom number operation (PPNO), with the functions
  PPNO-Query and PPNO-SHA-512-DRNG;
- load count to block boundary (LCBB).

Patches from Vadim Barkov (vbrkov@gmail.com), with coordination, testing
and format cleanups from Andreas Arnez (arnez@linux.ibm.com).