remove BLI_strnlen, use _strnlen as strnlen on windows.

cant test on windows but from what I can tell this exists like _vsnprintf

source/blender/blenlib/BLI_string.h

@@ -128,7 +128,6 @@ char *BLI_strcasestr(const char *s, const char *find);
 int BLI_strcasecmp(const char *s1, const char *s2);
 int BLI_strncasecmp(const char *s1, const char *s2, int n);
 int BLI_natstrcmp(const char *s1, const char *s2);
-size_t BLI_strnlen(const char *str, size_t maxlen);
 
 void BLI_timestr(double _time, char *str); /* time var is global */
 

source/blender/blenlib/intern/BLI_dynstr.c

@@ -39,6 +39,9 @@
 #ifndef vsnprintf
 #define vsnprintf _vsnprintf
 #endif
+#ifndef strnlen
+#define strnlen _strnlen
+#endif
 #endif
 
 /***/
@@ -83,7 +86,7 @@ void BLI_dynstr_append(DynStr *ds, const char *cstr) {
 
 void BLI_dynstr_nappend(DynStr *ds, const char *cstr, int len) {
 	DynStrElem *dse= malloc(sizeof(*dse));
-	int cstrlen= BLI_strnlen(cstr, len);
+	int cstrlen= strnlen(cstr, len);
 
 	dse->str= malloc(cstrlen+1);
 	memcpy(dse->str, cstr, cstrlen);

source/blender/blenlib/intern/string.c

@@ -342,9 +342,3 @@ void BLI_timestr(double _time, char *str)
 	str[11]=0;
 }
 
-/* determine the length of a fixed-size string */
-size_t BLI_strnlen(const char *str, size_t maxlen)
-{
-	const char *end = memchr(str, '\0', maxlen);
-	return end ? (size_t) (end - str) : maxlen;
-}