[lldb] Move Host::SystemLog out of !defined(_WIN32)

The definition of Host::SystemLog was (unintentionally) guarded by
!defined(_WIN32).

Author: JDevlieghere

lldb/source/Host/common/Host.cpp

@@ -90,6 +90,10 @@ int __pthread_fchdir(int fildes);
 using namespace lldb;
 using namespace lldb_private;
 
+#if !defined(__APPLE__)
+void Host::SystemLog(llvm::StringRef message) { llvm::errs() << message; }
+#endif
+
 #if !defined(__APPLE__) && !defined(_WIN32)
 static thread_result_t
 MonitorChildProcessThreadFunction(::pid_t pid,
@@ -106,10 +110,6 @@ llvm::Expected<HostThread> Host::StartMonitoringChildProcess(
   });
 }
 
-#if !defined(__APPLE__)
-void Host::SystemLog(llvm::StringRef message) { llvm::errs() << message; }
-#endif
-
 #ifndef __linux__
 // Scoped class that will disable thread canceling when it is constructed, and
 // exception safely restore the previous value it when it goes out of scope.