random_bigint_from_range: shifting instead of powering

Author: NegaScout

src/utils/random.jl

@@ -1,4 +1,4 @@
 function random_bigint_from_range(bits::Integer)
     bits <= 0 && error("bits <= 0")
-    return rand((BigInt(2)^(bits - 1)):(BigInt(2)^bits))
+    return rand((BigInt(2)<<(bits - 1)):(BigInt(2)<<bits))
 end