Merge remote-tracking branch 'remotes/rth/tags/pull-hppa-20190312' into staging

Misc fixes affecting HP-UX 10.20.

# gpg: Signature made Tue 12 Mar 2019 16:16:32 GMT
# gpg:                using RSA key 64DF38E8AF7E215F
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [full]
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A  05C0 64DF 38E8 AF7E 215F

* remotes/rth/tags/pull-hppa-20190312:
  target/hppa: exit TB if either Data or Instruction TLB changes
  target/hppa: add TLB protection id check
  target/hppa: allow multiple itlbp without itlba
  target/hppa: fix b,gate instruction
  target/hppa: ignore DIAG opcode
  target/hppa: remove PSW I/R/Q bit check
  target/hppa: add TLB trace events
  target/hppa: report ITLB_EXCP_MISS for ITLB misses
  target/hppa: fix TLB handling for page 0
  target/hppa: fix overwriting source reg in addb
  target/hppa: Check for page crossings in use_goto_tb

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>