Merge remote-tracking branch 'remotes/stsquad/tags/pull-softfloat-headers-190819...

Merge remote-tracking branch 'remotes/stsquad/tags/pull-softfloat-headers-190819-1' into staging

Softfloat updates

  - minor refactoring of constants
  - drop LIT64 macro
  - re-organise header inclusion

# gpg: Signature made Mon 19 Aug 2019 12:08:37 BST
# gpg:                using RSA key 6685AE99E75167BCAFC8DF35FBD0DB095A9E2A44
# gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>" [full]
# Primary key fingerprint: 6685 AE99 E751 67BC AFC8  DF35 FBD0 DB09 5A9E 2A44

* remotes/stsquad/tags/pull-softfloat-headers-190819-1:
  targets (various): use softfloat-helpers.h where we can
  target/riscv: rationalise softfloat includes
  target/mips: rationalise softfloat includes
  fpu: rename softfloat-specialize.h -> .inc.c
  fpu: make softfloat-macros "self-contained"
  fpu: move inline helpers into a separate header
  fpu: remove the LIT64 macro
  target/m68k: replace LIT64 with UINT64_C macros
  fpu: replace LIT64 with UINT64_C macros
  fpu: use min/max values from stdint.h for integral overflow
  fpu: convert float[16/32/64]_squash_denormal to new modern style
  fpu: replace LIT64 usage with UINT64_C for specialize constants

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