feat: add consts benchmark and missing items in __private

Signed-off-by: not-matthias <matthias@codspeed.io>

Author: not-matthias

crates/divan_compat/benches/basic_example.rs

@@ -32,6 +32,38 @@ fn mut_borrow(bencher: Bencher) {
     });
 }
 
+// Examples taken from the docs: https://docs.rs/divan/latest/divan/attr.bench.html#consts
+mod const_bench {
+    const LEN: usize = 42;
+
+    const fn len() -> usize {
+        4
+    }
+
+    #[codspeed_divan_compat::bench(consts = [1000, LEN, len()])]
+    fn init_array<const N: usize>() -> [i32; N] {
+        let mut result = [0; N];
+
+        #[allow(clippy::needless_range_loop)]
+        for i in 0..N {
+            result[i] = divan::black_box(i as i32);
+        }
+
+        result
+    }
+
+    const SIZES: &[usize] = &[1, 10, LEN, len()];
+    #[codspeed_divan_compat::bench(consts = SIZES)]
+    fn bench_array1<const N: usize>() -> [i32; N] {
+        init_array::<N>()
+    }
+
+    #[codspeed_divan_compat::bench(consts = SIZES)]
+    fn bench_array2<const N: usize>() -> [i32; N] {
+        init_array::<N>()
+    }
+}
+
 fn main() {
     codspeed_divan_compat::main();
 }

crates/divan_compat/src/compat/entry/mod.rs

@@ -16,7 +16,7 @@ use super::{
     BenchArgsRunner,
 };
 
-pub use generic::{EntryType, GenericBenchEntry};
+pub use generic::{EntryConst, EntryType, GenericBenchEntry};
 
 /// Benchmark entries generated by `#[divan::bench]`.
 ///

crates/divan_compat/src/compat/mod.rs

@@ -4,12 +4,12 @@ pub mod __private {
     pub use super::{
         bench::{BenchArgs, BenchOptions},
         entry::{
-            BenchEntry, BenchEntryRunner, EntryList, EntryLocation, EntryMeta, EntryType,
-            GenericBenchEntry, GroupEntry, BENCH_ENTRIES, GROUP_ENTRIES,
+            BenchEntry, BenchEntryRunner, EntryConst, EntryList, EntryLocation, EntryMeta,
+            EntryType, GenericBenchEntry, GroupEntry, BENCH_ENTRIES, GROUP_ENTRIES,
         },
     };
 
-    pub use divan::__private::{Arg, ToStringHelper};
+    pub use divan::__private::{shrink_array, Arg, ToStringHelper};
 }
 
 mod bench;