[SystemZ][z/OS] Create html report file with text flag

[fanbo-meng]

Summary

Change OF_None to OF_Text flag in file creation, same reasoning as https://reviews.llvm.org/D97785

[abhina.sreeskantharajan]

LGTM

clang/lib/StaticAnalyzer/Core/HTMLDiagnostics.cpp

void HTMLDiagnostics::ReportDiag(const PathDiagnostic& D,
   if (std::error_code EC = llvm::sys::fs::make_absolute(ResultPath)) {
     llvm::errs() << "warning: could not make '" << ResultPath
                  << "' absolute: " << EC.message() << '\n';
     return;
   }
 
   if (std::error_code EC = llvm::sys::fs::openFileForReadWrite(
           ResultPath, FD, llvm::sys::fs::CD_CreateNew,
-          llvm::sys::fs::OF_None)) {
+          llvm::sys::fs::OF_Text)) {
     // Existence of the file corresponds to the situation where a different
     // Clang instance has emitted a bug report with the same issue hash.
     // This is an entirely normal situation that does not deserve a warning,
     // as apart from hash collisions this can happen because the reports
     // are in fact similar enough to be considered duplicates of each other.
     if (EC != llvm::errc::file_exists) {
       llvm::errs() << "warning: could not create file in '" << Directory
                    << "': " << EC.message() << '\n';