Remove .gitattributes, add comment to lineendings.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@311732 91177308-0d34-0410-b5e6-96231b3b80d8

test/Frontend/.gitattributes

@@ -1,2 +0,0 @@
-# Below test validates crlf line endings, so it should stay crlf.
-system-header-line-directive-ms-lineendings.c text eol=crlf

test/Frontend/system-header-line-directive-ms-lineendings.c

@@ -5,7 +5,7 @@
 #include "line-directive.h"
 
 // This tests that the line numbers for the current file are correctly outputted
-// for the include-file-completed test case.  
+// for the include-file-completed test case. This file should be CRLF.
 
 // CHECK: # 1 "{{.*}}system-header-line-directive-ms-lineendings.c" 2
 // CHECK: # 1 "{{.*}}noline.h" 1 3