Merge remote-tracking branch 'remotes/rth/tcg-ppc-merge-1' into staging

* remotes/rth/tcg-ppc-merge-1: (25 commits)
  tcg-ppc: Use the return address as a base pointer
  tcg-ppc: Merge cache-utils into the backend
  qemu/osdep: Remove the need for qemu_init_auxval
  tcg-ppc: Rename the tcg/ppc64 backend
  tcg-ppc: Remove the backend
  tcg-ppc64: Merge ppc32 shifts
  tcg-ppc64: Support mulsh_i32
  tcg-ppc64: Merge ppc32 register usage
  tcg-ppc64: Merge ppc32 qemu_ld/st
  tcg-ppc64: Merge ppc32 brcond2, setcond2, muluh
  tcg-ppc64: Begin merging ppc32 with ppc64
  tcg-ppc64: Fix sub2 implementation
  tcg-ppc64: Merge 32-bit ABIs into the prologue / frame code
  tcg-ppc64: Adjust tcg_out_call for ELFv2
  tcg-ppc64: Support the ppc64 elfv2 ABI
  tcg-ppc64: Use the correct test in tcg_out_call
  tcg-ppc64: Better parameterize the stack frame
  tcg-ppc64: Fix TCG_TARGET_CALL_STACK_OFFSET
  tcg-ppc64: Move call macros out of tcg-target.h
  tcg-ppc64: Make TCG_AREG0 and TCG_REG_CALL_STACK enum constants
  ...

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