Merge branch 'bugfix/segv'

src/kyut/pass/operand_swapping_extractor.cpp

@@ -68,9 +68,11 @@ namespace kyut::pass {
             OperandSwappingExtractingVisitor visitor{writer_};
 
             for (const auto &func : module->functions) {
+                if (func->body) {
                     visitor.visit(func->body);
                 }
             }
+        }
 
     private:
         BitWriter &writer_;

src/kyut/pass/operand_swapping_watermarker.cpp

@@ -70,9 +70,11 @@ namespace kyut::pass {
             OperandSwappingWatermarkingVisitor visitor{stream_};
 
             for (const auto &func : module->functions) {
+                if (func->body) {
                     visitor.visit(func->body);
                 }
             }
+        }
 
     private:
         CircularBitStream &stream_;