go/printer: refine handling of one-line functions
Functions that "fit" on one line and were on one
line in the original source are not broken up into
two lines anymore simply because they contain a comment.
- Fine-tuned use of separating blanks after /*-style comments, so:
( /* extra blank after this comment */ )
(a int /* no extra blank after this comment*/)
- Factored out comment state (from printer state) into commentInfo.
- No impact on $GOROOT/src, misc formatting.
Fixes #5543.
LGTM=r
R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/
68630043