Merge pull request #80370 from cachemeifyoucan/eng/PR-147971980

[IRGen] Fix non-deterministic requests in addAbstractForFulfillments()

Author: cachemeifyoucan

lib/IRGen/Fulfillment.h

@@ -18,9 +18,9 @@
 #ifndef SWIFT_IRGEN_FULFILLMENT_H
 #define SWIFT_IRGEN_FULFILLMENT_H
 
-#include "llvm/ADT/DenseMap.h"
-#include "swift/AST/Types.h"
+#include "llvm/ADT/MapVector.h"
 #include "swift/AST/GenericSignature.h"
+#include "swift/AST/Types.h"
 #include "swift/IRGen/GenericRequirement.h"
 #include "MetadataPath.h"
 
@@ -49,7 +49,7 @@ struct Fulfillment {
 };
 
 class FulfillmentMap {
-  llvm::DenseMap<GenericRequirement, Fulfillment> Fulfillments;
+  llvm::MapVector<GenericRequirement, Fulfillment> Fulfillments;
 
 public:
   struct InterestingKeysCallback {