Move .ident handling to MCStreamer.

No functionality change, but exposes the API so that codegen can use it too.

Patch by Katya Romanova.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192757 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCMachOStreamer.cpp b/lib/MC/MCMachOStreamer.cpp
index 78c0094..2924dcd 100644
--- a/lib/MC/MCMachOStreamer.cpp
+++ b/lib/MC/MCMachOStreamer.cpp
@@ -82,7 +82,11 @@
     // FIXME: Just ignore the .file; it isn't important enough to fail the
     // entire assembly.
 
-    //report_fatal_error("unsupported directive: '.file'");
+    // report_fatal_error("unsupported directive: '.file'");
+  }
+
+  virtual void EmitIdent(StringRef IdentString) {
+    llvm_unreachable("macho doesn't support this directive");
   }
 
   virtual void FinishImpl();