cmd/gc: conversion should permit trailing comma after argument

[griesemer]

With the newly accepted spec change ( http://golang.org/cl/6572049/ ), all
conversions must accept a trailing comma after the argument to be converted. The
following program should compile w/o errors:

package p

var (
    _ = int(1.0,)      // comma is permitted
    _ = []byte("foo",) // syntax error: unexpected comma
    _ = chan int(nil,) // syntax error: unexpected comma
    _ = (func())(nil,) // syntax error: unexpected comma
)

[rsc]

Comment 1:

Labels changed: added priority-later, go1.1, removed priority-triage.

[rsc]

Comment 2:

Labels changed: added size-m.

[rsc]

Comment 3:

This issue was closed by revision ffc742b.

Status changed to Fixed.