Merge remote-tracking branch 'remotes/philmd-gitlab/tags/target_renesas_rx-20200320...

Merge remote-tracking branch 'remotes/philmd-gitlab/tags/target_renesas_rx-20200320' into staging

Introduce the architectural part of the Renesas RX
architecture emulation, developed by Yoshinori Sato.

CI jobs results:
  https://gitlab.com/philmd/qemu/pipelines/127886344
  https://travis-ci.org/github/philmd/qemu/builds/664579420

# gpg: Signature made Fri 20 Mar 2020 10:27:32 GMT
# gpg:                using RSA key FAABE75E12917221DCFD6BB2E3E32C2CDEADC0DE
# gpg: Good signature from "Philippe Mathieu-Daudé (F4BUG) <f4bug@amsat.org>" [full]
# Primary key fingerprint: FAAB E75E 1291 7221 DCFD  6BB2 E3E3 2C2C DEAD C0DE

* remotes/philmd-gitlab/tags/target_renesas_rx-20200320:
  Add rx-softmmu
  target/rx: Dump bytes for each insn during disassembly
  target/rx: Collect all bytes during disassembly
  target/rx: Emit all disassembly in one prt()
  target/rx: Use prt_ldmi for XCHG_mr disassembly
  target/rx: Replace operand with prt_ldmi in disassembler
  target/rx: Disassemble rx_index_addr into a string
  target/rx: RX disassembler
  target/rx: CPU definitions
  target/rx: TCG helpers
  target/rx: TCG translation
  MAINTAINERS: Add entry for the Renesas RX architecture
  hw/registerfields.h: Add 8bit and 16bit register macros

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