[release-branch.go1.15] cmd/compile: propagate go:notinheap implicitly
//go:notinheap
type T int
type U T
We already correctly propagate the notinheap-ness of T to U. But we
have an assertion in the typechecker that if there's no explicit
//go:notinheap associated with U, then report an error. Get rid of
that error so that implicit propagation is allowed.
Adjust the tests so that we make sure that uses of types like U
do correctly report an error when U is used in a context that might
cause a Go heap allocation.
Update #41432
Change-Id: I1692bc7cceff21ebb3f557f3748812a40887118d
Reviewed-on: https://go-review.googlesource.com/c/go/+/255637
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
(cherry picked from commit
22053790fa2c0944df53ea95df476ad2f855424f)
Reviewed-on: https://go-review.googlesource.com/c/go/+/255697
Trust: Keith Randall <khr@golang.org>
Reviewed-by: Austin Clements <austin@google.com>