spec: clarify that slice a expression shares underlying array with operand

The spec was not very precise as to what happens with respect to sharing
if a sliced operand is (a pointer to) an array. Added a small clarification
and a supporting example.

Fixes #31689.

Change-Id: Ic49351bec2033abd3f5428154ec3e9a7c2c9eaa5
Reviewed-on: https://go-review.googlesource.com/c/go/+/177139
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

0 files changed, 0 insertions, 0 deletions