fixup: include stdlib in kernel case

tested with:
cargo run --features executable -- bundle ~/miden/miden-base/miden-lib/asm/kernels/transaction/lib --kernel ~/miden/miden-base/miden-lib/asm/kernels/transaction/api.masm

miden/src/cli/bundle.rs

@@ -5,6 +5,7 @@ use assembly::{
     Assembler, KernelLibrary, Library, LibraryNamespace,
 };
 use clap::Parser;
+use stdlib::StdLibrary;
 
 #[derive(Debug, Clone, Parser)]
 #[clap(
@@ -39,7 +40,7 @@ impl BundleCmd {
         println!("Build library");
         println!("============================================================");
 
-        let assembler = Assembler::default().with_debug_mode(self.debug);
+        let mut assembler = Assembler::default().with_debug_mode(self.debug);
 
         // write the masl output
         let output_file = match &self.output {
@@ -55,6 +56,7 @@ impl BundleCmd {
         match &self.kernel {
             Some(kernel) => {
                 assert!(kernel.is_file(), "kernel must be a file");
+                let () = assembler.add_library(StdLibrary::default())?;
                 let library = KernelLibrary::from_dir(kernel, Some(&self.dir), assembler)?;
                 library.write_to_file(output_file).into_diagnostic()?;
                 println!(