FileCheck: Switch "possible match" calculation to use StringRef::edit_distance.
 - Thanks Doug, who is obviously less lazy than me!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94795 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/FileCheck/FileCheck.cpp b/utils/FileCheck/FileCheck.cpp
index 078028a..440d7d7 100644
--- a/utils/FileCheck/FileCheck.cpp
+++ b/utils/FileCheck/FileCheck.cpp
@@ -340,12 +340,7 @@
   if (ExampleString.empty())
     ExampleString = RegExStr;
 
-  unsigned Distance = 0;
-  for (unsigned i = 0, e = ExampleString.size(); i != e; ++i)
-    if (Buffer.substr(i, 1) != ExampleString.substr(i, 1))
-      ++Distance;
-
-  return Distance;
+  return Buffer.substr(0, ExampleString.size()).edit_distance(ExampleString);
 }
 
 void Pattern::PrintFailureInfo(const SourceMgr &SM, StringRef Buffer,