SDCC Fixes: Change some prototypes and some assumptions about the size of...

SDCC Fixes:  Change some prototypes and some assumptions about the size of unsigned int to get to a clean SDCC compile.

include/signal.h

@@ -297,7 +297,7 @@ int sigfillset(FAR sigset_t *set);
 int sighold(int signo);
 int sigismember(FAR const sigset_t *set, int signo);
 int sigignore(int signo);
-CODE void (*signal(int signo, CODE void (*func)(int signo)))(int signo);
+_sa_handler_t signal(int signo, _sa_handler_t func);
 int sigpause(int signo);
 int sigpending(FAR sigset_t *set);
 int sigprocmask(int how, FAR const sigset_t *set, FAR sigset_t *oset);
@@ -307,7 +307,7 @@ int sigqueue(int pid, int signo, union sigval value);
 int sigqueue(int pid, int signo, FAR void *sival_ptr);
 #endif
 int sigrelse(int signo);
-CODE void (*sigset(int signo, CODE void (*func)(int signo)))(int signo);
+_sa_handler_t sigset(int signo, _sa_handler_t func);
 int sigtimedwait(FAR const sigset_t *set, FAR struct siginfo *value,
                  FAR const struct timespec *timeout);
 int sigsuspend(FAR const sigset_t *sigmask);

libc/fixedmath/lib_ubsqrt.c

@@ -66,7 +66,7 @@ ub16_t ub32sqrtub16(ub32_t a)
     {
       /* Avoid 'xk + n / xk' overflow on first iteration. */
 
-      xk = 1ULL << 63;
+      xk = (uint64_t)1 << 63;
     }
 
   do
@@ -112,7 +112,7 @@ ub8_t ub16sqrtub8(ub16_t a)
     {
       /* Avoid 'xk + n / xk' overflow on first iteration. */
 
-      xk = 1U << 31;
+      xk = (uint32_t)1 << 31;
     }
 
   do

libc/signal/signal.c

 /****************************************************************************
  * libc/signal/signal.c
  *
- *   Copyright (C) 2015-2016 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2015-2017 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -70,7 +70,7 @@
  *
  ****************************************************************************/
 
-CODE void (*signal(int signo, CODE void (*func)(int signo)))(int signo)
+_sa_sighandler_t signal(int signo, _sa_handler_t func);
 {
   struct sigaction act;
   struct sigaction oact;