[lld/mac] Prefix errors with "ld64.lld" instead of just "lld"

[thakis]

Summary

Matches the ELF and COFF ports, which use ld.lld and lld-link, respectively.

While here, also move up cleanupCallback to match ELF / COFF.

[dblaikie]

@int3 please include some text when approving patches in Phab - otherwise Phab doesn't send email to the list, making it look like patches are being submitted without approval.

[int3]

Oh I had no idea. Will keep that in mind

lld/MachO/Driver.cpp

static uint32_t parseDylibVersion(const opt::ArgList& args, unsigned id) {
   return version.rawValue();
 }
 
 bool macho::link(ArrayRef<const char *> argsArr, bool canExitEarly,
                  raw_ostream &stdoutOS, raw_ostream &stderrOS) {
   lld::stdoutOS = &stdoutOS;
   lld::stderrOS = &stderrOS;
 
+  errorHandler().cleanupCallback = []() { freeArena(); };
+
+  errorHandler().logName = args::getFilenameWithoutExe(argsArr[0]);
   stderrOS.enable_colors(stderrOS.has_colors());
   // TODO: Set up error handler properly, e.g. the errorLimitExceededMsg
 
-  errorHandler().cleanupCallback = []() { freeArena(); };
 
   MachOOptTable parser;
   opt::InputArgList args = parser.parse(argsArr.slice(1));
 
   if (args.hasArg(OPT_help_hidden)) {
     parser.printHelp(argsArr[0], /*showHidden=*/true);
     return true;
   }