Windows 10 SDK build fixes

Build without Win32.mak, and using Universal C Runtime (UCRT)

windows: Check for APPVER, not VCVER for UCRT

When deciding whether UCRT is used (and thus no CRT merge modules), check for
Windows 10 rather than the version of Visual Studio, as we may be building with
an older SDK.

lib/roken/roken.h.in

@@ -356,7 +356,16 @@ ROKEN_CPP_START
 
 #define fsync   _commit
 
-/* The MSVC implementation of snprintf is not C99 compliant.  */
+#define timezone    _timezone
+
+#define tzname  _tzname
+
+#define _PIPE_BUFFER_SZ 8192
+#define pipe(fds) _pipe((fds), _PIPE_BUFFER_SZ, O_BINARY);
+
+#define ftruncate(fd, sz) _chsize((fd), (sz))
+
+#if !defined(HAVE_UCRT)
 #define snprintf    rk_snprintf
 #define vsnprintf   rk_vsnprintf
 #define vasnprintf  rk_vasnprintf
@@ -364,11 +373,6 @@ ROKEN_CPP_START
 #define asnprintf   rk_asnprintf
 #define asprintf    rk_asprintf
 
-#define _PIPE_BUFFER_SZ 8192
-#define pipe(fds) _pipe((fds), _PIPE_BUFFER_SZ, O_BINARY);
-
-#define ftruncate(fd, sz) _chsize((fd), (sz))
-
 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 rk_snprintf (char *str, size_t sz, const char *format, ...);
 
@@ -386,6 +390,7 @@ rk_vasnprintf (char **ret, size_t max_sz, const char *format, va_list args);
 
 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 rk_vsnprintf (char *str, size_t sz, const char *format, va_list args);
+#endif /* !defined(HAVE_UCRT) */
 
 /* missing stat.h predicates */
 

lib/roken/strtoll.c

@@ -38,6 +38,8 @@
 
 #include "roken.h"
 
+#ifndef HAVE_STRTOLL
+
 /* #include <sys/cdefs.h> */
 
 #include <limits.h>
@@ -150,3 +152,4 @@ noconv:
 	*endptr = (char *)(any ? s - 1 : nptr);
     return ret;
 }
+#endif /* !HAVE_STRTOLL */

lib/roken/strtoull.c

@@ -38,6 +38,8 @@
 
 #include "roken.h"
 
+#ifndef HAVE_STRTOULL
+
 /* #include <sys/cdefs.h> */
 
 #include <limits.h>
@@ -124,3 +126,4 @@ noconv:
 	*endptr = (char *)(any ? s - 1 : nptr);
     return (acc);
 }
+#endif /* !HAVE_STRTOULL */