* Makefile.in: Build wincap.o.

* wincap.cc: New file.
        * wincap.h: Ditto.
        * autoload.cc: Add dynamic load statement for `CreateHardLinkA'.
        * dcrt0.cc (os_being_run): Eliminated.
        (osname): Ditto.
        (iswinnt): Ditto.
        (set_os_type): Ditto.
        (dll_crt0_1): Call wincap.init() instead of set_os_type().
        (_dll_crt0): Ditto.
        * environ.cc (set_chunksize): New function.
        (parse_thing): `forkchunk' setting now invokes function `set_chunksize'.
        * fork.cc (chunksize): Eliminated. Moved to be member of wincap.
        * host_dependent.h: Removed.
        * syscalls.cc (_link): Try using `CreateHardLinkA' first, if available.
        * cygheap.cc, dcrt0.cc, delqueue.cc, dir.cc,
        environ.cc, fhandler.cc, fhandler.h, fhandler_console.cc,
        fhandler_mem.cc, fork.cc, mmap.cc, net.cc, pinfo.cc, pinfo.h,
        security.cc, syscalls.cc, sysconf.cc, syslog.cc, thread.cc,
        times.cc, tty.cc, uinfo.cc, uname.cc, winsup.h: Use new wincap
        capability check throughout.
        * winsup.h: Include wincap.h. Eliminate extern declarations of
        `os_being_run' and `iswinnt'. Eliminate `os_type" definition.
        * include/cygwin/version.h: Bump version to 1.3.4.

winsup/cygwin/thread.cc

@@ -499,7 +499,7 @@ int
 pthread_cond::TimedWait (DWORD dwMilliseconds)
 {
   DWORD rv;
-  if (!iswinnt)
+  if (!wincap.has_signal_object_and_wait ())
     {
       // FIXME: race condition (potentially drop events
       // Possible solution (single process only) - place this in a critical section.
@@ -621,7 +621,7 @@ pthread_mutex::pthread_mutex (pthread_mutexattr *attr):verifyable_object (PTHREA
       magic = 0;
       return;
     }
-  if (iswinnt)
+  if (wincap.has_try_enter_critical_section ())
     InitializeCriticalSection (&criticalsection);
   else
     {
@@ -637,7 +637,7 @@ pthread_mutex::pthread_mutex (pthread_mutexattr *attr):verifyable_object (PTHREA
 
 pthread_mutex::~pthread_mutex ()
 {
-  if (iswinnt)
+  if (wincap.has_try_enter_critical_section ())
     DeleteCriticalSection (&criticalsection);
   else
     {
@@ -663,7 +663,7 @@ pthread_mutex::~pthread_mutex ()
 int
 pthread_mutex::Lock ()
 {
-  if (iswinnt)
+  if (wincap.has_try_enter_critical_section ())
     {
       EnterCriticalSection (&criticalsection);
       return 0;
@@ -676,7 +676,7 @@ pthread_mutex::Lock ()
 int
 pthread_mutex::TryLock ()
 {
-  if (iswinnt)
+  if (wincap.has_try_enter_critical_section ())
     return (!TryEnterCriticalSection (&criticalsection));
   return (WaitForSingleObject (win32_obj_id, 0) == WAIT_TIMEOUT);
 }
@@ -684,7 +684,7 @@ pthread_mutex::TryLock ()
 int
 pthread_mutex::UnLock ()
 {
-  if (iswinnt)
+  if (wincap.has_try_enter_critical_section ())
     {
       LeaveCriticalSection (&criticalsection);
       return 0;
@@ -699,7 +699,7 @@ pthread_mutex::fixup_after_fork ()
   if (pshared != PTHREAD_PROCESS_PRIVATE)
     api_fatal("pthread_mutex::fixup_after_fork () doesn'tunderstand PROCESS_SHARED mutex's\n");
   /* FIXME: duplicate code here and in the constructor. */
-  if (iswinnt)
+  if (wincap.has_try_enter_critical_section ())
     InitializeCriticalSection(&criticalsection);
   else
     {