Expose the InstructionDeleter's callbacks

so they don't need to be passed around on the side everywhere.

Author: atrick

include/swift/SILOptimizer/Utils/InstOptUtils.h

@@ -248,12 +248,12 @@ class InstructionDeleter {
   InstructionDeleter(InstModCallbacks chainedCallbacks = InstModCallbacks())
       : deadInstructions(), iteratorRegistry(chainedCallbacks) {}
 
-  InstModCallbacks &getCallbacks() { return iteratorRegistry.getCallbacks(); }
-
   UpdatingInstructionIteratorRegistry &getIteratorRegistry() {
     return iteratorRegistry;
   }
 
+  InstModCallbacks &getCallbacks() { return iteratorRegistry.getCallbacks(); }
+
   llvm::iterator_range<UpdatingInstructionIterator>
   updatingRange(SILBasicBlock *bb) {
     return iteratorRegistry.makeIteratorRange(bb);
@@ -264,6 +264,12 @@ class InstructionDeleter {
     return iteratorRegistry.makeReverseIteratorRange(bb);
   }
 
+  bool hadCallbackInvocation() const {
+    return const_cast<InstructionDeleter *>(this)
+        ->getCallbacks()
+        .hadCallbackInvocation();
+  }
+
   /// If the instruction \p inst is dead, record it so that it can be cleaned
   /// up.
   ///