Remove warning about default covering no cases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175846 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/IR/Attributes.cpp b/lib/IR/Attributes.cpp
index 84d14b4..11ed82d 100644
--- a/lib/IR/Attributes.cpp
+++ b/lib/IR/Attributes.cpp
@@ -356,8 +356,6 @@
 uint64_t AttributeImpl::getAttrMask(Attribute::AttrKind Val) {
   // FIXME: Remove this.
   switch (Val) {
-  default:
-    llvm_unreachable("Unsupported attribute type");
   case Attribute::EndAttrKinds:
     llvm_unreachable("Synthetic enumerators which should never get here");
 
@@ -395,7 +393,8 @@
   case Attribute::ThreadSafety:    return 1ULL << 36;
   case Attribute::UninitializedChecks: return 1ULL << 37;
   case Attribute::NoBuiltin:       return 1ULL << 38;
- }
+  }
+  llvm_unreachable("Unsupported attribute type");
 }
 
 //===----------------------------------------------------------------------===//