[30.0.0] asm: avoid propagating arbitrary (#10295)

* asm: avoid propagating `arbitrary` (#10217)

This is something that @alexcrichton already fixed over in the assembler
crate--no need to implement `Arbitrary` unnecessarily. It's unclear how
this stayed in here in `cranelift-codegen` but this change removes it.

* Update release notes

---------

Co-authored-by: Andrew Brown <[email protected]>

Author: alexcrichton

Cargo.lock

@@ -8,6 +8,11 @@ Released 2025-02-25.
   fix an issue caused by #9929.
   [#10290](https://github.com/bytecodealliance/wasmtime/pull/10290)
 
+### Changed
+
+* The `cranelift-codegen` crate now no longer depends on `arbitrary`, a
+  now-unnecessary dependency.
+  [#10217](https://github.com/bytecodealliance/wasmtime/pull/10217)
 
 --------------------------------------------------------------------------------
 

RELEASES.md

@@ -21,7 +21,6 @@ workspace = true
 features = ["all-arch"]
 
 [dependencies]
-arbitrary = { version = "1.3.2", features = ["derive"] }
 anyhow = { workspace = true, optional = true, features = ['std'] }
 bumpalo = "3"
 capstone = { workspace = true, optional = true }

cranelift/codegen/Cargo.toml

@@ -5,7 +5,6 @@ use super::{
     SyntheticAmode, VCodeConstant, WritableGpr,
 };
 use crate::ir::TrapCode;
-use arbitrary::Arbitrary;
 use cranelift_assembler_x64 as asm;
 
 /// Define the types of registers Cranelift will use.
@@ -42,12 +41,6 @@ impl asm::AsReg for PairedGpr {
     }
 }
 
-impl<'a> Arbitrary<'a> for PairedGpr {
-    fn arbitrary(_: &mut arbitrary::Unstructured<'a>) -> arbitrary::Result<Self> {
-        unimplemented!("assembler fuzzing is not implemented at this level")
-    }
-}
-
 /// This bridges the gap between codegen and assembler register types.
 impl asm::AsReg for Gpr {
     fn enc(&self) -> u8 {
@@ -59,12 +52,6 @@ impl asm::AsReg for Gpr {
     }
 }
 
-impl<'a> Arbitrary<'a> for Gpr {
-    fn arbitrary(_: &mut arbitrary::Unstructured<'a>) -> arbitrary::Result<Self> {
-        unimplemented!("assembler fuzzing is not implemented at this level")
-    }
-}
-
 /// A helper method for extracting the hardware encoding of a register.
 #[inline]
 fn enc(gpr: &Gpr) -> u8 {