Replace ArrayRef<T>() with None, now that we have an implicit ArrayRef constructor from None

Patch by Robert Wilhelm.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181139 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index c19fe27..6b809cf 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -2009,7 +2009,7 @@
                                    PartialDiagnostic PDiag,
                                    SourceLocation StringLoc,
                                    bool IsStringLocation, Range StringRange,
-                            ArrayRef<FixItHint> Fixit = ArrayRef<FixItHint>());
+                                   ArrayRef<FixItHint> Fixit = None);
 
 protected:
   bool HandleInvalidConversionSpecifier(unsigned argIndex, SourceLocation Loc,
@@ -2036,7 +2036,7 @@
   template <typename Range>
   void EmitFormatDiagnostic(PartialDiagnostic PDiag, SourceLocation StringLoc,
                             bool IsStringLocation, Range StringRange,
-                            ArrayRef<FixItHint> Fixit = ArrayRef<FixItHint>());
+                            ArrayRef<FixItHint> Fixit = None);
 
   void CheckPositionalAndNonpositionalArgs(
       const analyze_format_string::FormatSpecifier *FS);