runtime/cgo: preserve VRs across crosscall_ppc64 on linux
Rework this function to closely match the PPC64 crosscall2, but
written in gnu asm. Likewise, fix this to store TOC in the new
frame, not the caller's, as is required by the ELF ABIs.
Change-Id: I8902c74f2607e3436260882a7bea52e72a67b8f9
Reviewed-on: https://go-review.googlesource.com/c/go/+/486335 Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Run-TryBot: Paul Murphy <murp@ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com> Reviewed-by: Carlos Amedee <carlos@golang.org>
Auto-Submit: Carlos Amedee <carlos@golang.org>