cmd/compile: ensure stenciled function bodies are nonempty
Our compiler gets confused between functions that were declared
with no body, and those which have a body but it is empty.
Ensure that when stenciling, we generate a nonempty body.
The particular test that causes this problem is in
cmd/compile/internal/gc/main.go:enqueueFunc. It thinks that if
a function has no body, then we need to generate ABI wrappers for
it, but not compile it.
Fixes #49524
Change-Id: Id962666a2098f60a2421484b6a776eafdc4f4a63
Reviewed-on: https://go-review.googlesource.com/c/go/+/363395
Trust: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Dan Scales <danscales@google.com>