[dev.typeparams] runtime: call cgocallbackg indirectly on ARM64

This is CL 312669, for ARM64.

cgocallback calls cgocallbackg after switching the stack. Call it
indirectly to bypass the linker's nosplit check. In particular,
this avoids a nosplit stack overflow on Windows when register ABI
is enabled.

Change-Id: I7054a750fb0ec2579d46004f94b46b6f7b9e3a21
Reviewed-on: https://go-review.googlesource.com/c/go/+/324734


Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>