EIP4844: Refactor precompile to use bytes-based verify_kzg_proof()

See ethereum/consensus-specs#3097 for the changes to the verify_kzg_proof API

EIPS/eip-4844.md

@@ -255,22 +255,23 @@ The precompile costs `POINT_EVALUATION_PRECOMPILE_GAS` and executes the followin
 
 ```python
 def point_evaluation_precompile(input: Bytes) -> Bytes:
-    # Verify P(z) = a
-    # versioned hash: first 32 bytes
+    """
+    Verify p(z) = y given commitment that corresponds to the polynomial p(x) and a KZG proof.
+    Also verify that the provided commitment matches the provided versioned_hash.
+    """
+    # The data is encoded as follows: versioned_hash | z | y | commitment | proof |
     versioned_hash = input[:32]
-    # Evaluation point: next 32 bytes
-    x = int.from_bytes(input[32:64], 'little')
-    assert x < BLS_MODULUS
-    # Expected output: next 32 bytes
-    y = int.from_bytes(input[64:96], 'little')
-    assert y < BLS_MODULUS
-    # The remaining data will always be the proof, including in future versions
-    # input kzg point: next 48 bytes
-    data_kzg = input[96:144]
-    assert kzg_to_versioned_hash(data_kzg) == versioned_hash
-    # Quotient kzg: next 48 bytes
-    quotient_kzg = input[144:192]
-    assert verify_kzg_proof(data_kzg, x, y, quotient_kzg)
+    z = input[32:64]
+    y = input[64:96]
+    commitment = input[96:144]
+    kzg_proof = input[144:192]
+
+    # Verify KZG proof
+    assert verify_kzg_proof(commitment, z, y, kzg_proof)
+
+    # Verify commitment matches versioned_hash
+    assert kzg_to_versioned_hash(commitment) == versioned_hash
+
     return Bytes([])
 ```