Add static cast to unsigned char whenever a character classification function is called with a signed char argument, in order to avoid assertions in Windows Debug configuration.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175006 91177308-0d34-0410-b5e6-96231b3b80d8

utils/FileCheck/FileCheck.cpp

@@ -242,7 +242,7 @@ bool Pattern::ParsePattern(StringRef PatternStr, SourceMgr &SM,
       }
 
       // Name can't start with a digit.
-      if (isdigit(Name[0])) {
+      if (isdigit(static_cast<unsigned char>(Name[0]))) {
         SM.PrintMessage(SMLoc::getFromPointer(Name.data()), SourceMgr::DK_Error,
                         "invalid name in named regex");
         return true;