Merge remote-tracking branch 'remotes/shorne/tags/pull-or-20180703' into staging

Merge remote-tracking branch 'remotes/shorne/tags/pull-or-20180703' into staging

OpenRISC cleanups and Fixes for QEMU 3.0

Mostly patches from Richard Henderson fixing multiple things:
 * Fix singlestepping in GDB.
 * Use more TB linking.
 * Fixes to exit TB after updating SPRs to enable registering of state
   changes.
 * Significant optimizations and refactors to the TLB
 * Split out disassembly from translation.
 * Add qemu-or1k to qemu-binfmt-conf.sh.
 * Implement signal handling for linux-user.

Then there are a few fixups from me:
 * Fix delay slot detections to match hardware, this was masking a bug
   in the linus kernel.
 * Fix stores to the PIC mask register

# gpg: Signature made Tue 03 Jul 2018 14:44:10 BST
# gpg:                using RSA key C3B31C2D5E6627E4
# gpg: Good signature from "Stafford Horne <shorne@gmail.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: D9C4 7354 AEF8 6C10 3A25  EFF1 C3B3 1C2D 5E66 27E4

* remotes/shorne/tags/pull-or-20180703: (25 commits)
  target/openrisc: Fix writes to interrupt mask register
  target/openrisc: Fix delay slot exception flag to match spec
  linux-user: Fix struct sigaltstack for openrisc
  linux-user: Implement signals for openrisc
  target/openrisc: Add support in scripts/qemu-binfmt-conf.sh
  target/openrisc: Reorg tlb lookup
  target/openrisc: Increase the TLB size
  target/openrisc: Stub out handle_mmu_fault for softmmu
  target/openrisc: Use identical sizes for ITLB and DTLB
  target/openrisc: Fix cpu_mmu_index
  target/openrisc: Fix tlb flushing in mtspr
  target/openrisc: Reduce tlb to a single dimension
  target/openrisc: Merge mmu_helper.c into mmu.c
  target/openrisc: Remove indirect function calls for mmu
  target/openrisc: Merge tlb allocation into CPUOpenRISCState
  target/openrisc: Form the spr index from tcg
  target/openrisc: Exit the TB after l.mtspr
  target/openrisc: Split out is_user
  target/openrisc: Link more translation blocks
  target/openrisc: Fix singlestep_enabled
  ...

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