Merge remote-tracking branch 'remotes/rth/tags/pull-tcg-20200228' into staging

Fix race in cpu_exec_step_atomic.
Work around compile failure with -fno-inine.
Expand tcg/arm epilogue inline.
Adjustments to the default code gen buffer size.

# gpg: Signature made Sat 29 Feb 2020 02:13:43 GMT
# gpg:                using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg:                issuer "richard.henderson@linaro.org"
# 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-tcg-20200228:
  accel/tcg: increase default code gen buffer size for 64 bit
  accel/tcg: only USE_STATIC_CODE_GEN_BUFFER on 32 bit hosts
  accel/tcg: remove link between guest ram and TCG cache size
  accel/tcg: use units.h for defining code gen buffer sizes
  tcg/arm: Expand epilogue inline
  tcg/arm: Split out tcg_out_epilogue
  compiler.h: Don't use compile-time assert when __NO_INLINE__ is defined
  accel/tcg: fix race in cpu_exec_step_atomic (bug 1863025)

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