[SIL] NFC: Added ValueBase::getUsers.

Make iterating user instructions a bit easier.

Author: nate-chandler

include/swift/SIL/SILValue.h

@@ -466,9 +466,15 @@ class ValueBase : public SILNode, public SILAllocated<ValueBase> {
   /// entire use list.
   inline bool hasTwoUses() const;
 
-  /// Helper struct for DowncastUserFilterRange
+  /// Helper struct for DowncastUserFilterRange and UserRange
   struct UseToUser;
 
+  using UserRange =
+      llvm::iterator_range<llvm::mapped_iterator<swift::ValueBaseUseIterator,
+                                                 swift::ValueBase::UseToUser,
+                                                 swift::SILInstruction *>>;
+  inline UserRange getUsers() const;
+
   template <typename Subclass>
   using DowncastUserFilterRange =
       DowncastFilterRange<Subclass,
@@ -1439,6 +1445,10 @@ struct ValueBase::UseToUser {
   SILInstruction *operator()(Operand &use) { return use.getUser(); }
 };
 
+inline ValueBase::UserRange ValueBase::getUsers() const {
+  return llvm::map_range(getUses(), ValueBase::UseToUser());
+}
+
 template <typename T>
 inline ValueBase::DowncastUserFilterRange<T> ValueBase::getUsersOfType() const {
   auto begin = llvm::map_iterator(use_begin(), UseToUser());