Changed to static_cast, due to post-commit review.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173980 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/Diagnostic.cpp b/lib/Basic/Diagnostic.cpp
index 1097980..6627ad6 100644
--- a/lib/Basic/Diagnostic.cpp
+++ b/lib/Basic/Diagnostic.cpp
@@ -744,8 +744,8 @@
         const char *Pipe = ScanFormat(Argument, Argument + ArgumentLen, '|');
         const char *FirstDollar = ScanFormat(Argument, Pipe, '$');
         const char *SecondDollar = ScanFormat(FirstDollar + 1, Pipe, '$');
-        const char ArgStr1[] = { '%', (char)('0' + ArgNo) };
-        const char ArgStr2[] = { '%', (char)('0' + ArgNo2) };
+        const char ArgStr1[] = { '%', static_cast<char>('0' + ArgNo) };
+        const char ArgStr2[] = { '%', static_cast<char>('0' + ArgNo2) };
         FormatDiagnostic(Argument, FirstDollar, OutStr);
         FormatDiagnostic(ArgStr1, ArgStr1 + 2, OutStr);
         FormatDiagnostic(FirstDollar + 1, SecondDollar, OutStr);