[llvm-reduce] add ReduceAttribute delta pass

Summary:
The output from llvm-reduce still has significantly more attributes than
bugpoint does.  Teach llvm-reduce to remove attributes.

Reviewers: diegotf, dblaikie, george.burgess.iv

Subscribers: mgorny, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73853
diff --git a/llvm/tools/llvm-reduce/DeltaManager.h b/llvm/tools/llvm-reduce/DeltaManager.h
index 2309c3a..595f130 100644
--- a/llvm/tools/llvm-reduce/DeltaManager.h
+++ b/llvm/tools/llvm-reduce/DeltaManager.h
@@ -14,11 +14,12 @@
 #include "TestRunner.h"
 #include "deltas/Delta.h"
 #include "deltas/ReduceArguments.h"
+#include "deltas/ReduceAttributes.h"
 #include "deltas/ReduceBasicBlocks.h"
 #include "deltas/ReduceFunctions.h"
 #include "deltas/ReduceGlobalVars.h"
-#include "deltas/ReduceMetadata.h"
 #include "deltas/ReduceInstructions.h"
+#include "deltas/ReduceMetadata.h"
 
 namespace llvm {
 
@@ -30,6 +31,7 @@
   reduceMetadataDeltaPass(Tester);
   reduceArgumentsDeltaPass(Tester);
   reduceInstructionsDeltaPass(Tester);
+  reduceAttributesDeltaPass(Tester);
   // TODO: Implement the remaining Delta Passes
 }