Multiplication overflow detection for integer width > 64 bits (#988)

* mul overflow > 64 bits

Signed-off-by: salaheldinsoliman <[email protected]>

Cargo.toml

@@ -16,7 +16,8 @@ cc = "1.0"
 
 [dependencies]
 regex = "1"
-num-bigint = "0.4"
+rand = "0.8"
+num-bigint = { version = "0.4", features = ["rand"]}
 num-traits = "0.2"
 num-integer = "0.1.44"
 parity-wasm = "0.45"
@@ -56,7 +57,8 @@ num-derive = "0.3"
 parity-scale-codec = "3.1"
 ethabi = "17.0"
 wasmi = "0.11"
-rand = "0.7"
+# rand version 0.7 is needed for ed25519_dalek::keypair::generate, used in solana_tests/signature_verify.rs
+rand_07 = { package = "rand", version = "0.7" }
 sha2 = "0.10"
 # solana_rbpf makes api changes in patch versions
 solana_rbpf = "=0.2.32"