reflect: keep pointer register results alive in callMethod
When callMethod calls the underlying method, after reflectcall
it gets the result registers in "Ints" slots but not in "Ptrs"
slots. If the GC runs at this point, it may lose track of those
pointers and free the memory they point to.
To make sure the GC sees the pointer results, copy "Ints" to
"Ptrs", and keep them alive until we return to the caller.
This fixes test/fixedbugs/issue27695.go with register ABI.
Change-Id: I4092c91bcbd6954683740a12d91d689900446875
Reviewed-on: https://go-review.googlesource.com/c/go/+/309909
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>