auto merge of #9936 : madjar/rust/master, r=alexcrichton

This should close #9468.

I removed the test stating that nested comments should not be implemented.

I had a little chicken-and-egg problem because a comment of the std contains "/*", and adding support for nested comment creates a backward incompatibility in that case, so I had to use a dirty hack to get stage1 and stage2 to compile. This part should be revert when this commit lands in a snapshot.

This is my first non-typo contribution, so I'm open to any comment.

src/libstd/os.rs

@@ -546,12 +546,6 @@ pub fn self_exe_path() -> Option<Path> {
     load_self().and_then(|path| Path::new_opt(path).map(|mut p| { p.pop(); p }))
 }
 
-
-/**
- * Returns the path to the user's home directory, if known.
-}
-
-
 /**
  * Returns the path to the user's home directory, if known.
  *