go/printer: do not panic on *ast.ParenExpr in combinesWithName
Fixes #69206
Change-Id: I1b5a664c22d5739e2c6748d562591f57345b536e
GitHub-Last-Rev:
1798e2c65b3c2c0c1ef674b000dce2636c834783
GitHub-Pull-Request: golang/go#69208
Reviewed-on: https://go-review.googlesource.com/c/go/+/610115
Reviewed-by: Robert Griesemer <gri@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Robert Griesemer <gri@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>