Do some minor reformatting of 'extern "C"' use throughout.

* autoload.cc (GetSystemTimes): Define new autoload function.
* fhandler_proc.cc (proc_listing): Add cpuinfo and partitions entries.
(fhandler_proc::fill_filebuf): Add PROC_CPUINFO and PROC_PARTITIONS cases.
(format_proc_uptime): Use GetSystemTimes if available.
(read_value): New macro.
(print): New macro.
(cpuid): New function.
(can_set_flag): New function.
(format_proc_cpuinfo): New function.
(format_proc_partitions): New function.

winsup/cygwin/tty.cc

@@ -28,22 +28,19 @@ details. */
 
 extern fhandler_tty_master *tty_master;
 
-extern "C"
-int
+extern "C" int
 grantpt (int fd)
 {
   return 0;
 }
 
-extern "C"
-int
+extern "C" int
 unlockpt (int fd)
 {
   return 0;
 }
 
-extern "C"
-int
+extern "C" int
 ttyslot (void)
 {
   if (NOTSTATE (myself, PID_USETTY))