Fix typos in comments, and delete an unused function.

llvm-svn: 137352
diff --git a/llvm/lib/Transforms/Scalar/ObjCARC.cpp b/llvm/lib/Transforms/Scalar/ObjCARC.cpp
index 6b5dfc2..f3f9149 100644
--- a/llvm/lib/Transforms/Scalar/ObjCARC.cpp
+++ b/llvm/lib/Transforms/Scalar/ObjCARC.cpp
@@ -1194,10 +1194,6 @@
       if (RefCount != 0) --RefCount;
     }
 
-    void ClearRefCount() {
-      RefCount = 0;
-    }
-
     bool IsKnownIncremented() const {
       return RefCount > 0;
     }
@@ -1364,7 +1360,7 @@
                              /*TopDown=*/true);
   }
 
-  // For each entry in our set, if the other set doens't have an entry with the
+  // For each entry in our set, if the other set doesn't have an entry with the
   // same key, force it to merge with an empty entry.
   for (ptr_iterator MI = top_down_ptr_begin(),
        ME = top_down_ptr_end(); MI != ME; ++MI)
@@ -1389,7 +1385,7 @@
                              /*TopDown=*/false);
   }
 
-  // For each entry in our set, if the other set doens't have an entry
+  // For each entry in our set, if the other set doesn't have an entry
   // with the same key, force it to merge with an empty entry.
   for (ptr_iterator MI = bottom_up_ptr_begin(),
        ME = bottom_up_ptr_end(); MI != ME; ++MI)