rm more reference

core/vm/contracts.go

@@ -420,19 +420,6 @@ func runBn256Pairing(input []byte) ([]byte, error) {
 	return false32Byte, nil
 }
 
-type ringSignatureVerifier struct{}
-type bulletproofVerifier struct{}
-
-func (c *bulletproofVerifier) RequiredGas(input []byte) uint64 {
-	//the gas should depends on the ringsize
-	return 100000
-}
-
-func (c *ringSignatureVerifier) RequiredGas(input []byte) uint64 {
-	//the gas should depends on the ringsize
-	return 100000
-}
-
 // bn256PairingIstanbul implements a pairing pre-compile for the bn256 curve
 // conforming to Istanbul consensus rules.
 type bn256PairingIstanbul struct{}