Auto-import std::core. Fix module assignment of declarations. Introspection improvements. Deref null error panics in safe mode. Support for LLVM 15

lib/std/array.c3

@@ -2,7 +2,6 @@
 // Use of this source code is governed by the MIT license
 // a copy of which can be found in the LICENSE_STDLIB file.
 module std::array;
-import std::mem;
 
 /**
  * @require elements > 0