Include _cgo_export.h generated header file.

function.c

 #include <sqlite3.h>
 #include <stdlib.h>
-
-extern void goXAuxDataDestroy(void *ad);
+#include "_cgo_export.h"
 
 void goSqlite3SetAuxdata(sqlite3_context *ctx, int N, void *ad) {
 	sqlite3_set_auxdata(ctx, N, ad, goXAuxDataDestroy);
 }
 
-extern void goXFunc(sqlite3_context *ctx, void *udf, void *goctx, int argc, sqlite3_value **argv);
-extern void goXStep(sqlite3_context *ctx, void *udf, int argc, sqlite3_value **argv);
-extern void goXFinal(sqlite3_context *ctx, void *udf);
-extern void goXDestroy(void *pApp);
-
 static void cXFunc(sqlite3_context *ctx, int argc, sqlite3_value **argv) {
 	void *udf = sqlite3_user_data(ctx);
 	void *goctx = sqlite3_get_auxdata(ctx, 0);

hook.c

@@ -3,6 +3,7 @@
 // license that can be found in the LICENSE file.
 
 #include <sqlite3.h>
+//#include "_cgo_export.h"
 
 extern int goXCommitHook(void *udp);
 

trace.c

@@ -4,12 +4,14 @@
 
 #include <sqlite3.h>
 #include <stdlib.h>
+//#include "_cgo_export.h"
 
 extern void goXTrace(void *udp, const char *sql);
 
 void goSqlite3Trace(sqlite3 *db, void *udp) {
 	sqlite3_trace(db, goXTrace, udp);
 }
+
 extern void goXProfile(void *udp, const char *sql, sqlite3_uint64 nanoseconds);
 
 void goSqlite3Profile(sqlite3 *db, void *udp) {