build: do not define _POSIX_C_SOURCE on NetBSD (#4196)

It leads to missing symbols, see #4180.

(cherry picked from commit 2bf04d1f04)

---------

Co-authored-by: Thomas Klausner <wiz@gatalith.at>

lib/src/portable/endian.h

@@ -18,16 +18,20 @@
 #if defined(HAVE_ENDIAN_H) || \
     defined(__linux__) || \
     defined(__GNU__) || \
+    defined(__NetBSD__) || \
     defined(__OpenBSD__) || \
     defined(__CYGWIN__) || \
     defined(__MSYS__) || \
     defined(__EMSCRIPTEN__)
 
+#if defined(__NetBSD__)
+#define _NETBSD_SOURCE 1
+#endif
+
 # include <endian.h>
 
 #elif defined(HAVE_SYS_ENDIAN_H) || \
     defined(__FreeBSD__) || \
-    defined(__NetBSD__) || \
     defined(__DragonFly__)
 
 # include <sys/endian.h>

lib/src/query.c

@@ -1,3 +1,12 @@
+/*
+ * On NetBSD, defining standard requirements like this removes symbols
+ * from the namespace; however, we need non-standard symbols for
+ * endian.h.
+ */
+#if defined(__NetBSD__) && defined(_POSIX_C_SOURCE)
+#undef _POSIX_C_SOURCE
+#endif
+
 #include "tree_sitter/api.h"
 #include "./alloc.h"
 #include "./array.h"