Switch new .file directive emission off by default, change llc's flag for it to
-enable-dwarf-directory.

llvm-svn: 143326
diff --git a/llvm/lib/Target/TargetMachine.cpp b/llvm/lib/Target/TargetMachine.cpp
index 3f58e84..daac924 100644
--- a/llvm/lib/Target/TargetMachine.cpp
+++ b/llvm/lib/Target/TargetMachine.cpp
@@ -198,7 +198,7 @@
     MCSaveTempLabels(false),
     MCUseLoc(true),
     MCUseCFI(true),
-    MCUseDwarfDirectory(true) {
+    MCUseDwarfDirectory(false) {
   // Typically it will be subtargets that will adjust FloatABIType from Default
   // to Soft or Hard.
   if (UseSoftFloat)