Do not add newline in empty blocks.

void f() {}
now gets formatted in one line.

llvm-svn: 172067
diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index c0ed6c5..39efeab 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -1033,6 +1033,8 @@
     if (Left.is(tok::at) &&
         Right.FormatTok.Tok.getObjCKeywordID() != tok::objc_not_keyword)
       return false;
+    if (Left.is(tok::l_brace) && Right.is(tok::r_brace))
+      return false;
     return true;
   }