feat: Implement initial LLVM backend with coroutine support and runtime function integration.

Author: ProgrammerKR

include/object.h

@@ -148,6 +148,8 @@ struct ObjDictionary {
   Table items;
 };
 
+typedef struct ObjTask ObjTask;
+
 struct ObjTask {
   Obj obj;
   void* coroHandle; // LLVM Coroutine Handle

src/compiler/backend_llvm.cpp

@@ -473,8 +473,7 @@ class LLVMEmitter {
             false
         );
         llvm::Function::Create(AwaitType, llvm::Function::ExternalLinkage, "prox_rt_await", ModuleOb.get());
-    }
-
+    
         // Value prox_rt_run_and_wait(Value task)
         llvm::FunctionType *RunWaitType = llvm::FunctionType::get(
             Builder->getInt64Ty(),