Subzero: Improve class definition hygiene.

src/IceConditionCodesX8632.h

Index: src/IceConditionCodesX8632.h
diff --git a/src/IceConditionCodesX8632.h b/src/IceConditionCodesX8632.h
index a930bf895ae9276bc933d8b56a80b3374bbca4bd..77dd4c753c06e6c8dc49573e490beacba6811cb5 100644
--- a/src/IceConditionCodesX8632.h
+++ b/src/IceConditionCodesX8632.h
@@ -20,6 +20,10 @@
 namespace Ice {
 
 class CondX86 {
+  CondX86() = delete;
+  CondX86(const CondX86 &) = delete;
+  CondX86 &operator=(const CondX86 &) = delete;
+
 public:
   // An enum of condition codes used for branches and cmov. The enum value
   // should match the value used to encode operands in binary instructions.