Don't remove trailing escaped newline from line comments.

llvm-svn: 190175
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 0f46003..57aa9ca 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -789,6 +789,8 @@
   EXPECT_EQ("int aaaaaaa, bbbbbbb; // comment",
             format("int aaaaaaa, bbbbbbb; // comment                   ",
                    getLLVMStyleWithColumns(33)));
+  EXPECT_EQ("// comment\\\n", format("// comment\\\n  \t \v   \f   "));
+  EXPECT_EQ("// comment    \\\n", format("// comment    \\\n  \t \v   \f   "));
 }
 
 TEST_F(FormatTest, UnderstandsBlockComments) {