refactor: validating private call data (#6316)

Please read [contributing guidelines](CONTRIBUTING.md) and remove this
line.

noir-projects/noir-protocol-circuits/crates/private-kernel-lib/src/kernel_circuit_public_inputs_composer.nr

@@ -129,7 +129,9 @@ impl KernelCircuitPublicInputsComposer {
 
     fn silo_note_hashes(&mut self) {
         let first_nullifier = self.public_inputs.end.new_nullifiers.get_unchecked(0).value();
-        assert(first_nullifier != 0, "The 0th nullifier in the accumulated nullifier array is zero");
+
+        // This check is unnecessary. The 0th nullifier will always be set a non-zero value in private_kernel_init.
+        // assert(first_nullifier != 0, "The 0th nullifier in the accumulated nullifier array is zero");
 
         let note_hashes = self.public_inputs.end.new_note_hashes.storage;
         for i in 0..MAX_NEW_NOTE_HASHES_PER_TX {

noir-projects/noir-protocol-circuits/crates/private-kernel-lib/src/lib.nr

@@ -1,14 +1,13 @@
 mod kernel_circuit_public_inputs_composer;
+mod private_call_data_validator;
 mod private_kernel_circuit_public_inputs_composer;
 mod private_kernel_init;
 mod private_kernel_inner;
 mod private_kernel_tail;
 mod private_kernel_tail_to_public;
+mod tests;
 
 use private_kernel_init::PrivateKernelInitCircuitPrivateInputs;
 use private_kernel_inner::PrivateKernelInnerCircuitPrivateInputs;
 use private_kernel_tail::PrivateKernelTailCircuitPrivateInputs;
 use private_kernel_tail_to_public::PrivateKernelTailToPublicCircuitPrivateInputs;
-
-// TODO: rename to be precise as to what its common to.
-mod common;