[lldb] Make the system log a NOOP on Windows (llvm#112052)

Windows doesn't have a built-in system log. Previously we got away with
writing to stdout and stderr because it was used only sporadically. As
we're trying to make the system log more useful on the other platforms,
the increased use become a concern. Make it a NOOP until someone figures
out a reasonable alternative.

(cherry picked from commit 3dedcab)

Author: JDevlieghere

lldb/source/Host/common/Host.cpp

@@ -111,17 +111,7 @@ void Host::SystemLog(Severity severity, llvm::StringRef message) {
   syslog(level, "%s", message.data());
 }
 #else
-void Host::SystemLog(Severity severity, llvm::StringRef message) {
-  switch (severity) {
-  case lldb::eSeverityInfo:
-  case lldb::eSeverityWarning:
-    llvm::outs() << message;
-    break;
-  case lldb::eSeverityError:
-    llvm::errs() << message;
-    break;
-  }
-}
+void Host::SystemLog(Severity severity, llvm::StringRef message) {}
 #endif
 #endif