Add a section on the representation of values:
distinguish between values that are self-contained
and values that contain references while avoiding
the notion of "reference types" which is misleading.
Also, use "predeclared identifier nil" rather than
"predeclared value nil" because it is the identifier
that is predeclared.
Fixes #5083.
Change-Id: I2235673c6404f2c055f195e879f198c7ab246d58
Reviewed-on: https://go-review.googlesource.com/c/go/+/635801 Reviewed-by: Rob Pike <r@golang.org> Reviewed-by: David Chase <drchase@google.com>
Auto-Submit: Robert Griesemer <gri@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Bypass: Robert Griesemer <gri@google.com> Reviewed-by: Robert Griesemer <gri@google.com>