CHECK 2 done

Add support for handling generic types in LLVM backend

- Updated `lb_type_internal` to return a pointer type for unspecialized generics.
- Modified `write_type_to_canonical_string` to handle specialized generics without panicking.
- Enhanced `default_type` to return the default type of specialized generics when applicable.

src/llvm_backend_general.cpp

@@ -2212,6 +2212,14 @@ gb_internal LLVMTypeRef lb_type_internal(lbModule *m, Type *type) {
 
 	case Type_BitField:
 		return lb_type_internal(m, type->BitField.backing_type);
+        
+	case Type_Generic:
+		if (type->Generic.specialized) {
+			return lb_type_internal(m, type->Generic.specialized);
+		} else {
+			// For unspecialized generics, use a pointer type as a placeholder
+			return LLVMPointerType(LLVMInt8TypeInContext(m->ctx), 0);
+		}
 	}
 
 	GB_PANIC("Invalid type %s", type_to_string(type));