Fixed build for swift packages

Author: nferruzzi

Sources/SQLite/Core/Connection.swift

@@ -33,6 +33,9 @@ import CSQLite
 #else
 import SQLite3
 #endif
+#if SWIFT_PACKAGE
+import SQLiteObjc
+#endif
 
 /// A connection to SQLite.
 public final class Connection {

Sources/SQLiteObjc/SQLiteObjc.m

@@ -138,7 +138,7 @@ int _SQLiteRegisterTokenizer(sqlite3 *db, const char * moduleName, const char *
 }
 
 void _SQLite_dispatch_async_and_wait(dispatch_queue_t queue, __attribute__((__noescape__)) dispatch_block_t block) {
-    if (@available(iOS 12.0, *)) {
+    if (@available(macOS 10.14, iOS 12.0, *)) {
         dispatch_async_and_wait(queue, block);
     } else {
         dispatch_sync(queue, block);