Newline added after block comment with trailing space

[Xanewok]

I think I hit #1177, here is a simple diff and some context:

root@20a4a53558f8:/# rustfmt --check file.rs
Diff in /file.rs at line 1:
-/**/
-fn main() {}
-
+/**/
+
+fn main() {}

root@20a4a53558f8:/# cat file.rs
/**/
fn main() {}

root@20a4a53558f8:/# rustfmt --version
rustfmt 1.0.3-nightly (d6829d6 2019-02-14) # Same thing happens with rustfmt 1.0.1-stable (be13559 2018-12-10)

What's important is that there is trailing whitespace after /**/ , which seems to be required to reproduce this issue.