Basic NetBSD support needed to build GDC

src/core/stdc/assert_.d

@@ -53,6 +53,13 @@ else version (FreeBSD)
      */
     void __assert(const(char)* exp, const(char)* file, uint line);
 }
+else version (NetBSD)
+{
+    /***
+     * Assert failure function in the NetBSD C library.
+     */
+    void __assert(const(char)* file, int line, const(char)* exp);
+}
 else version (DragonFlyBSD)
 {
     /***

src/core/stdc/wchar_.d

@@ -40,6 +40,15 @@ version (CRuntime_Glibc)
         ___value __value;
     }
 }
+else version (NetBSD)
+{
+    union __mbstate_t
+    {
+        int64_t   __mbstateL;
+        char[128] __mbstate8;
+    }
+    alias mbstate_t = __mbstate_t;
+}
 else version (OpenBSD)
 {
     union __mbstate_t

src/core/sys/netbsd/dlfcn.d

@@ -103,7 +103,7 @@ static if (__BSD_VISIBLE)
     //void*    fdlopen(int, int);
     int      dladdr(const(void)*, Dl_info*);
     //dlfunc_t dlfunc(void*, const(char)*);
-    //int      dlinfo(void*, int, void*);
+    int      dlinfo(void*, int, void*);
     /+void     dllockinit(void* _context,
         void* function(void* _context) _lock_create,
         void  function(void* _lock)    _rlock_acquire,