This reverts commit CL 99135 (git rev 1040626c).

Reason for revert: breaks valid code; see #27302

Fixes #27302
Updates #22907

Change-Id: I82bb0c28ae1683140c71e7a2224c4ded3f4acea1
Reviewed-on: https://go-review.googlesource.com/137716Reviewed-by: Ian Lance Taylor <iant@golang.org>