Normalize wasm types (#1378)

Normalize wasm types, for the two wasm types, if their parameter types
and result types are the same, we only save one copy, so as to reduce
the footprint and simplify the type comparison in opcode CALL_INDIRECT.

And fix issue in interpreter globals_instantiate, and remove used codes.

core/iwasm/aot/aot_runtime.h

@@ -633,9 +633,6 @@ aot_enlarge_memory(AOTModuleInstance *module_inst, uint32 inc_page_count);
  *
  * @return true if equal, false otherwise
  */
-bool
-aot_is_wasm_type_equal(AOTModuleInstance *module_inst, uint32 type1_idx,
-                       uint32 type2_idx);
 
 /**
  * Invoke native function from aot code