[Sema] Make typo correction slightly more efficient

edit_distance returns UpperBound+1 if the distance will exceed UpperBound. We can subtract 1 from UpperBound and change >= to > in the if condition. The threshold does not change but edit_distance will have more opportunity to bail out earlier.

llvm-svn: 341763
diff --git a/clang/lib/Sema/SemaLookup.cpp b/clang/lib/Sema/SemaLookup.cpp
index d0f133e..8cf8dae 100644
--- a/clang/lib/Sema/SemaLookup.cpp
+++ b/clang/lib/Sema/SemaLookup.cpp
@@ -3998,9 +3998,9 @@
 
   // Compute an upper bound on the allowable edit distance, so that the
   // edit-distance algorithm can short-circuit.
-  unsigned UpperBound = (TypoStr.size() + 2) / 3 + 1;
+  unsigned UpperBound = (TypoStr.size() + 2) / 3;
   unsigned ED = TypoStr.edit_distance(Name, true, UpperBound);
-  if (ED >= UpperBound) return;
+  if (ED > UpperBound) return;
 
   TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
   if (isKeyword) TC.makeKeyword();