remove const_eval_limit increase except for cfg(test), which needs it

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "const-crc32"
-version = "1.1.0"
+version = "1.2.0"
 edition = "2021"
 authors = ["Jonathan Strong <[email protected]>"]
 license = "MIT"

README.md

@@ -18,7 +18,10 @@ if used on dynamic data at runtime. Usage should generally be restricted to decl
 
 ## `#[const_eval_limit]`
 
-This crate sets `#[const_eval_limit]` to 1,000,000,000 to avoid hitting the limit when
-executing the `const fn`, which requires `#![feature(const_eval_limit)]`.
+You may need to increase the crate-wide `const_eval_limit` setting to use `const_crc32` for larger byte slices.
+
+Increating `const_eval_limit` requires the nightly-only `#![feature(const_eval_limit)]`.
+
+Previously, this crate set the limit itself, however, as of the 2022-10-30 nightly, the value set in `const_crc32` does not increase the limit for crates which use the library.
 
 Compile time for `const` data around 100k is less than 1s.

src/lib.rs

@@ -8,9 +8,8 @@
 //! assert_eq!(CKSUM, 0x414fa339_u32);
 //! ```
 
-#![feature(const_eval_limit)]
-
-#![const_eval_limit = "1000000000"]
+#![cfg_attr(test, feature(const_eval_limit))]
+#![cfg_attr(test, const_eval_limit = "0")]
 
 /// used to generate up a [u32; 256] lookup table in `crc32`. this computes
 /// the table on demand for a given "index" `i`