code review 5672062: go/printer, go/fmt: simpler exprList code, more tests

go/printer: simpler exprList code, more tests

Except for the tests, this is mostly deleting code:

- removed several exprListModes:
  blankStart: easily done explicitly, and trailing blanks
    are cleaned up by the trimmer post-pass
  blankEnd: never used
  commaSep: all exprLists calls had this set

- added test cases for multi-line returns
(for a later fix of issue 1207)

- no formatting changes

[gri, 2012-03-01 19:42:43]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://code.google.com/p/go

[rsc1, 2012-03-02 18:25:39]

LGTM

[gri, 2012-03-02 19:16:09]

*** Submitted as http://code.google.com/p/go/source/detail?r=d8586c9e6c89 ***

go/printer: simpler exprList code, more tests

Except for the tests, this is mostly deleting code:

- removed several exprListModes:
  blankStart: easily done explicitly, and trailing blanks
    are cleaned up by the trimmer post-pass
  blankEnd: never used
  commaSep: all exprLists calls had this set

- added test cases for multi-line returns
(for a later fix of issue 1207)

- no formatting changes

R=golang-dev, rsc
CC=golang-dev
http://codereview.appspot.com/5672062