Move ToU64 to bitcoin

diff --git a/bitcoin/src/bip158.rs b/bitcoin/src/bip158.rs
index d71b81c0..cbe0813b 100644
--- a/bitcoin/src/bip158.rs
+++ b/bitcoin/src/bip158.rs
@@ -41,7 +41,6 @@ use core::cmp::{self, Ordering};
 
 use hashes::{sha256d, siphash24};
 use internals::array::ArrayExt as _;
-use internals::ToU64 as _;
 use io::{BufRead, Write};
 
 use crate::block::{Block, BlockHash, Checked};
@@ -49,6 +48,7 @@ use crate::consensus::{ReadExt, WriteExt};
 use crate::prelude::{BTreeSet, Borrow, Vec};
 use crate::script::{ScriptPubKey, ScriptPubKeyExt as _};
 use crate::transaction::OutPoint;
+use crate::ToU64 as _;
 
 #[rustfmt::skip]                // Keep public re-exports separate.
 #[doc(no_inline)]
diff --git a/bitcoin/src/blockdata/block.rs b/bitcoin/src/blockdata/block.rs
index 996f3620..f481a310 100644
--- a/bitcoin/src/blockdata/block.rs
+++ b/bitcoin/src/blockdata/block.rs
@@ -8,7 +8,6 @@
 //! these blocks and the blockchain.
 
 use encoding::CompactSizeEncoder;
-use internals::ToU64;
 use io::{BufRead, Write};
 
 use crate::consensus::encode::{self, Decodable, Encodable, WriteExt as _};
@@ -18,7 +17,7 @@ use crate::pow::TargetExt as _;
 use crate::prelude::Vec;
 use crate::script::{PushBytesExt as _, ScriptExt as _};
 use crate::transaction::{Coinbase, Transaction, TransactionExt as _};
-use crate::{internal_macros, BlockTime, Target, Weight, Work};
+use crate::{internal_macros, BlockTime, Target, ToU64, Weight, Work};
 
 #[rustfmt::skip]                // Keep public re-exports separate.
 #[doc(inline)]
@@ -283,7 +282,7 @@ impl Decodable for Block<Unchecked> {
 
     #[inline]
     fn consensus_decode<R: io::BufRead + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
-        let mut r = io::Read::take(r, internals::ToU64::to_u64(encode::MAX_VEC_SIZE));
+        let mut r = io::Read::take(r, crate::ToU64::to_u64(encode::MAX_VEC_SIZE));
         let header = Decodable::consensus_decode(&mut r)?;
         let transactions = Decodable::consensus_decode(&mut r)?;
 
@@ -411,7 +410,6 @@ mod tests {
     use alloc::string::ToString;
 
     use hex::hex;
-    use internals::ToU64 as _;
 
     use super::*;
     use crate::consensus::encode::{deserialize, serialize};
diff --git a/bitcoin/src/blockdata/script/borrowed.rs b/bitcoin/src/blockdata/script/borrowed.rs
index 6f6c6d4e..5e9bac5a 100644
--- a/bitcoin/src/blockdata/script/borrowed.rs
+++ b/bitcoin/src/blockdata/script/borrowed.rs
@@ -3,7 +3,6 @@
 use core::fmt;
 
 use internals::array::ArrayExt; // For `split_first`.
-use internals::ToU64 as _;
 
 use super::witness_version::WitnessVersion;
 use super::{
@@ -20,7 +19,7 @@ use crate::prelude::{sink, String, ToString};
 use crate::script::{self, ScriptPubKeyBufExt as _};
 use crate::taproot::{LeafVersion, TapLeafHash, TapLeafHashExt as _, TapNodeHash};
 use crate::witness_program::P2A_PROGRAM;
-use crate::{internal_macros, Amount, FeeRate, ScriptPubKeyBuf, WitnessScriptBuf};
+use crate::{internal_macros, Amount, FeeRate, ScriptPubKeyBuf, ToU64 as _, WitnessScriptBuf};
 
 internal_macros::define_extension_trait! {
     /// Extension functionality for the [`Script`] type.
diff --git a/bitcoin/src/blockdata/script/owned.rs b/bitcoin/src/blockdata/script/owned.rs
index c3d59126..f9d18520 100644
--- a/bitcoin/src/blockdata/script/owned.rs
+++ b/bitcoin/src/blockdata/script/owned.rs
@@ -3,13 +3,10 @@
 #[cfg(doc)]
 use core::ops::Deref;
 
-use internals::ToU64 as _;
-
 use super::{
     opcode_to_verify, write_scriptint, Builder, Error, Instruction, PushBytes, ScriptBuf,
     ScriptExtPriv as _, ScriptPubKeyBuf, ScriptSigBuf, WitnessScript,
 };
-use crate::internal_macros;
 use crate::key::{
     FullPublicKey, LegacyPublicKey, PubkeyHash, TapTweak, TweakedPublicKey, UntweakedPublicKey,
     WPubkeyHash,
@@ -21,6 +18,7 @@ use crate::script::witness_program::{WitnessProgram, P2A_PROGRAM};
 use crate::script::witness_version::WitnessVersion;
 use crate::script::{self, ScriptHash, WScriptHash};
 use crate::taproot::TapNodeHash;
+use crate::{internal_macros, ToU64 as _};
 
 internal_macros::define_extension_trait! {
     /// Extension functionality for the [`ScriptBuf`] type.
diff --git a/bitcoin/src/blockdata/transaction.rs b/bitcoin/src/blockdata/transaction.rs
index e136700c..57ace5e7 100644
--- a/bitcoin/src/blockdata/transaction.rs
+++ b/bitcoin/src/blockdata/transaction.rs
@@ -13,7 +13,7 @@
 #[cfg(feature = "arbitrary")]
 use arbitrary::{Arbitrary, Unstructured};
 use encoding::CompactSizeEncoder;
-use internals::{const_casts, ToU64};
+use internals::const_casts;
 use io::{BufRead, Write};
 
 use super::Weight;
@@ -27,7 +27,7 @@ use crate::script::{
 #[cfg(doc)]
 use crate::sighash::{EcdsaSighashType, TapSighashType};
 use crate::witness::Witness;
-use crate::{internal_macros, Amount, FeeRate, Sequence, SignedAmount};
+use crate::{internal_macros, Amount, FeeRate, Sequence, SignedAmount, ToU64};
 
 #[rustfmt::skip]            // Keep public re-exports separate.
 #[doc(no_inline)]
diff --git a/bitcoin/src/consensus/encode.rs b/bitcoin/src/consensus/encode.rs
index 8837c691..15450d03 100644
--- a/bitcoin/src/consensus/encode.rs
+++ b/bitcoin/src/consensus/encode.rs
@@ -20,12 +20,12 @@ use core::{cmp, mem, slice};
 use encoding::{CompactSizeEncoder, Encoder};
 use hashes::{sha256, sha256d, Hash};
 use hex::DisplayHex as _;
-use internals::ToU64;
 use io::{BufRead, Cursor, Read, Write};
 
 use super::IterReader;
 use crate::prelude::{rc, sync, Box, Cow, String, Vec};
 use crate::taproot::TapLeafHash;
+use crate::ToU64;
 
 #[rustfmt::skip]                // Keep public re-exports separate.
 pub use super::{Error, FromHexError, ParseError, DeserializeError};
diff --git a/bitcoin/src/internal_macros.rs b/bitcoin/src/internal_macros.rs
index de9b54e2..c5f66d62 100644
--- a/bitcoin/src/internal_macros.rs
+++ b/bitcoin/src/internal_macros.rs
@@ -33,7 +33,7 @@ macro_rules! impl_consensus_encoding {
             fn consensus_decode<R: $crate::io::BufRead + ?Sized>(
                 r: &mut R,
             ) -> core::result::Result<$thing, $crate::consensus::encode::Error> {
-                let mut r = $crate::io::Read::take(r, internals::ToU64::to_u64($crate::consensus::encode::MAX_VEC_SIZE));
+                let mut r = $crate::io::Read::take(r, crate::ToU64::to_u64($crate::consensus::encode::MAX_VEC_SIZE));
                 Ok($thing {
                     $($field: $crate::consensus::Decodable::consensus_decode(&mut r)?),+
                 })
diff --git a/bitcoin/src/lib.rs b/bitcoin/src/lib.rs
index fc1a53e0..bcb4fdec 100644
--- a/bitcoin/src/lib.rs
+++ b/bitcoin/src/lib.rs
@@ -321,3 +321,31 @@ mod encode_impls {
     impl_encodable_for_u32_wrapper!(BlockHeight);
     impl_encodable_for_u32_wrapper!(BlockHeightInterval);
 }
+
+/// A conversion trait for unsigned integer types smaller than or equal to 64-bits.
+///
+/// This trait exists because [`usize`] doesn't implement `Into<u64>`. We only support 32 and 64 bit
+/// architectures because of consensus code so we can infallibly do the conversion.
+pub trait ToU64 {
+    /// Converts unsigned integer type to a [`u64`].
+    fn to_u64(self) -> u64;
+}
+
+macro_rules! impl_to_u64 {
+    ($($ty:ident),*) => {
+        $(
+            impl ToU64 for $ty { fn to_u64(self) -> u64 { self.into() } }
+        )*
+    }
+}
+impl_to_u64!(u8, u16, u32, u64);
+
+impl ToU64 for usize {
+    fn to_u64(self) -> u64 {
+        internals::const_assert!(
+            core::mem::size_of::<usize>() <= 8;
+            "platforms that have usize larger than 64 bits are not supported"
+        );
+        self as u64
+    }
+}
diff --git a/internals/src/lib.rs b/internals/src/lib.rs
index 4335b242..daa04c0a 100644
--- a/internals/src/lib.rs
+++ b/internals/src/lib.rs
@@ -46,31 +46,3 @@ pub mod slice;
 #[macro_use]
 pub mod serde;
 pub mod const_casts;
-
-/// A conversion trait for unsigned integer types smaller than or equal to 64-bits.
-///
-/// This trait exists because [`usize`] doesn't implement `Into<u64>`. We only support 32 and 64 bit
-/// architectures because of consensus code so we can infallibly do the conversion.
-pub trait ToU64 {
-    /// Converts unsigned integer type to a [`u64`].
-    fn to_u64(self) -> u64;
-}
-
-macro_rules! impl_to_u64 {
-    ($($ty:ident),*) => {
-        $(
-            impl ToU64 for $ty { fn to_u64(self) -> u64 { self.into() } }
-        )*
-    }
-}
-impl_to_u64!(u8, u16, u32, u64);
-
-impl ToU64 for usize {
-    fn to_u64(self) -> u64 {
-        crate::const_assert!(
-            core::mem::size_of::<usize>() <= 8;
-            "platforms that have usize larger than 64 bits are not supported"
-        );
-        self as u64
-    }
-}