bors bf27352953 auto merge of #4911 : lifthrasiir/rust/comment-exemptions, r=catamorphism
This is a natural extension of #4887, and handles the following three cases:

~~~~
a line with only /s
////////////////////////////////////////////

a line with only /s followed by whitespace
////////////////////////////////////////////         

a block comment with only *s between two /s
/********************************/
~~~~
2013-02-14 16:34:38 -08:00
..
2013-02-08 02:56:49 +09:00