[OSSA] Fix AccessPathDefUserTraversal::visitUser; ignore end_borrow.

Ignore end_borrow as a user of the access path. I don't think there's
any value in viewing it as a use of the access path because we really
care about address reads and writes in this context, not object
lifetime extension. Treating it as an access path use clutters the analysis,
and I'm afraid it will inhibit optimization.

Author: atrick

lib/SIL/Utils/MemAccessUtils.cpp

@@ -1440,6 +1440,9 @@ bool AccessPathDefUseTraversal::visitUser(DFSEntry dfs) {
       return true;
     }
   }
+  if (isa<EndBorrowInst>(use->getUser())) {
+    return true;
+  }
   // We weren't able to "see through" any more address conversions; so
   // record this as a use.