Remove this test. It is causing problems has has relatively little value

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@98730 91177308-0d34-0410-b5e6-96231b3b80d8

test/Misc/changed-files.c

@@ -1,3 +0,0 @@
-// RUN: touch %t.c
-// RUN: not %clang -E %t.c -o %t.c 2> %t.stderr
-// RUN: grep "modified" %t.stderr