ART: Enable Clang's -Wdeprecated

Replace throw() with noexcept.

Add default copy constructors and copy assignment constructors for
cases with destructors, as the implicit definition is deprecated.

Change-Id: Ice306a3f510b072b00bec4d4360f7c8055135c9d
diff --git a/cmdline/unit.h b/cmdline/unit.h
index 6b53b18..ad6a03d 100644
--- a/cmdline/unit.h
+++ b/cmdline/unit.h
@@ -24,6 +24,7 @@
   // Avoid 'Conditional jump or move depends on uninitialised value(s)' errors
   // when running valgrind by specifying a user-defined constructor.
   Unit() {}
+  Unit(const Unit&) = default;
   ~Unit() {}
   bool operator==(Unit) const {
     return true;