Prepare to multithread object generation

src/llvm_backend.hpp

@@ -90,8 +90,6 @@ struct lbModule {
 	CheckerInfo *info;
 	AstPackage *pkg; // associated
 
-	gbMutex mutex;
-
 	Map<LLVMTypeRef> types; // Key: Type *
 	Map<Type *> llvm_types; // Key: LLVMTypeRef
 	i32 internal_type_level;
@@ -127,6 +125,8 @@ struct lbModule {
 struct lbGenerator {
 	CheckerInfo *info;
 
+	gbMutex mutex;
+
 	Array<String> output_object_paths;
 	Array<String> output_temp_paths;
 	String   output_base;