bench: move bench behind cfg flag rather than Cargo feature

Cargo.toml

@@ -14,7 +14,6 @@ edition = "2018"
 compiler = []
 trace = []
 
-unstable = []
 serde = ["actual-serde", "bitcoin/serde", "elements/serde"]
 rand = ["bitcoin/rand"]
 base64 = ["bitcoin/base64"]

README.md

@@ -37,7 +37,7 @@ Enabling the `no-std` feature does not disable `std`. To disable the `std` featu
 
 ## Benchmarking
 
-To run the benchmarks run `RUSTFLAGS=--cfg=bench cargo +nightly bench`.
+To run the benchmarks run `RUSTFLAGS=--cfg=miniscript_bench cargo +nightly bench --all-features`.
 
 ## Minimum Supported Rust Version (MSRV)
 This library should always compile with any combination of features on **Rust 1.48.0**.

contrib/test.sh

@@ -67,7 +67,7 @@ fi
 # Bench if told to (this only works with the nightly toolchain)
 if [ "$DO_BENCH" = true ]
 then
-    RUSTFLAGS=--cfg=bench cargo bench --features="unstable compiler"
+    RUSTFLAGS=--cfg=miniscript_bench cargo bench --features="compiler"
 fi
 
 # Build the docs if told to (this only works with the nightly toolchain)

src/lib.rs

@@ -89,7 +89,7 @@
 //!
 //!
 
-#![cfg_attr(all(test, feature = "unstable"), feature(test))]
+#![cfg_attr(miniscript_bench, feature(test))]
 // Coding conventions
 #![allow(bare_trait_objects)]
 #![deny(non_camel_case_types)]
@@ -109,7 +109,7 @@ compile_error!(
 #[cfg(feature = "serde")]
 pub use actual_serde as serde;
 pub use {bitcoin, elements};
-#[cfg(all(test, feature = "unstable"))]
+#[cfg(miniscript_bench)]
 extern crate test;
 
 // Miniscript imports

src/policy/compiler.rs

@@ -1610,7 +1610,7 @@ mod tests {
     }
 }
 
-#[cfg(all(test, feature = "unstable"))]
+#[cfg(miniscript_bench)]
 mod benches {
     use std::str::FromStr;
 

src/policy/mod.rs

@@ -574,7 +574,7 @@ mod tests {
     }
 }
 
-#[cfg(all(test, feature = "compiler", feature = "unstable"))]
+#[cfg(all(miniscript_bench, feature = "compiler"))]
 mod benches {
     use core::str::FromStr;