Merge rust-bitcoin#4710: Update NumOpResult arbitrary impl to only consume 1 byte of entropy

453888a Update NumOpResult arbitrary impl to only consume 1 byte of entropy (Shing Him Ng)

Pull request description:

  Took some inspiration from [a comment](rust-bitcoin#4689 (comment)) in rust-bitcoin#4689 and looked through the rest of the codebase to update `u.int_in_range(0..=1)` to use `bool::arbitrary(u)`


ACKs for top commit:
  yancyribbens:
    cr ACK 453888a
  tcharding:
    ACK 453888a
  apoelstra:
    ACK 453888a; successfully ran local tests


Tree-SHA512: 2ee44d4bd06749be4a44b18a64e36f49a5e2b9ac9fb186b54615d8979b8bbb6b62e4a86255355bd15ed1b030eb415a3902a269b842b20c5bcf48a479ad62381c

Author: apoelstra

units/src/result.rs

@@ -325,10 +325,9 @@ impl fmt::Display for MathOp {
 #[cfg(feature = "arbitrary")]
 impl<'a, T: Arbitrary<'a>> Arbitrary<'a> for NumOpResult<T> {
     fn arbitrary(u: &mut Unstructured<'a>) -> arbitrary::Result<Self> {
-        let choice = u.int_in_range(0..=1)?;
-        match choice {
-            0 => Ok(NumOpResult::Valid(T::arbitrary(u)?)),
-            _ => Ok(NumOpResult::Error(NumOpError(MathOp::arbitrary(u)?))),
+        match bool::arbitrary(u)? {
+            true => Ok(NumOpResult::Valid(T::arbitrary(u)?)),
+            false => Ok(NumOpResult::Error(NumOpError(MathOp::arbitrary(u)?))),
         }
     }
 }