Use llvm::sys::fs::createUniqueFile.

Include a test that clang now produces output files with permissions matching
the umask.

llvm-svn: 185727
diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index 7d25ebb..c1f6bc5 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -2521,8 +2521,7 @@
   TempPath = File;
   TempPath += "-%%%%%%%%";
   int fd;
-  if (llvm::sys::fs::unique_file(TempPath.str(), fd, TempPath,
-                                 /*makeAbsolute=*/false))
+  if (llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath))
     return true;
 
   // FIXME: Can we somehow regenerate the stat cache here, or do we need to