Subzero: Improve class definition hygiene.

src/IceELFStreamer.h

Index: src/IceELFStreamer.h
diff --git a/src/IceELFStreamer.h b/src/IceELFStreamer.h
index ce70e86f8889066fc74a9e7644e3bc12f5807f2c..50e4dd72575bc31d3e6faca89a1b3d876b840fea 100644
--- a/src/IceELFStreamer.h
+++ b/src/IceELFStreamer.h
@@ -22,6 +22,10 @@ namespace Ice {
 // Low level writer that can that can handle ELFCLASS32/64.
 // Little endian only for now.
 class ELFStreamer {
+  ELFStreamer() = delete;
+  ELFStreamer(const ELFStreamer &) = delete;
+  ELFStreamer &operator=(const ELFStreamer &) = delete;
+
 public:
   explicit ELFStreamer(Fdstream &Out) : Out(Out) {}