go/printer: fix invalid output for empty decls
The current output for empty declarations such as var, const, import
results in "var", "const", "import" respectively. These are not valid
and the parser will promptly reject them as invalid syntax.
This CL updates this behavior by adding "()" to the output of empty
decls so the syntax becomes valid, e.g "var ()" instead of "var".
Fixes #63566
Change-Id: I571b182d9ccf71b159360c8de003ad55d0ff3443
GitHub-Last-Rev:
2720419e364938e9962be71d0e6ed51375fec404
GitHub-Pull-Request: golang/go#63593
Reviewed-on: https://go-review.googlesource.com/c/go/+/535995
Reviewed-by: Robert Griesemer <gri@google.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Mauri de Souza Meneguzzo <mauri870@gmail.com>