winch: Prepare for an update to the wasm-tools crates (#5238)

This commit prepares the `winch` crate for updating `wasm-tools`,
notably changing a bit about how the visitation of operators works. This
moves the function body and wasm validator out of the `CodeGen`
structure and into parameters threaded into the emission of the actual
function.

Additionally the `VisitOperator` implementation was updated to remove
the explicit calls to the validator, favoring instead a macro-generated
solution to guarantee that all validation happens before any translation
proceeds. This means that the `VisitOperator for CodeGen` impl is now
infallible and the various methods have been inlined into the trait
methods as well as removing the `Result<_>`.

Finally this commit updates translation to call `validator.finish(..)`
which is required to perform the final validation steps of the function
body.

winch/codegen/src/isa/aarch64/mod.rs

@@ -34,7 +34,7 @@ impl TargetIsa for Aarch64 {
     fn compile_function(
         &self,
         _sig: &FuncType,
-        mut _body: FunctionBody,
+        _body: &FunctionBody,
         mut _validator: FuncValidator<ValidatorResources>,
     ) -> Result<Vec<String>> {
         todo!()

winch/codegen/src/isa/mod.rs

@@ -85,7 +85,7 @@ pub trait TargetIsa: Send + Sync {
     fn compile_function(
         &self,
         sig: &FuncType,
-        body: FunctionBody,
+        body: &FunctionBody,
         validator: FuncValidator<ValidatorResources>,
     ) -> Result<Vec<String>>;
 

winch/codegen/src/isa/x64/mod.rs

@@ -47,9 +47,10 @@ impl TargetIsa for X64 {
     fn compile_function(
         &self,
         sig: &FuncType,
-        mut body: FunctionBody,
+        body: &FunctionBody,
         mut validator: FuncValidator<ValidatorResources>,
     ) -> Result<Vec<String>> {
+        let mut body = body.get_binary_reader();
         let masm = MacroAssembler::new();
         let stack = Stack::new();
         let abi = abi::X64ABI::default();
@@ -58,9 +59,8 @@ impl TargetIsa for X64 {
         // TODO Add in floating point bitmask
         let regalloc = RegAlloc::new(RegSet::new(ALL_GPR, 0), regs::scratch());
         let codegen_context = CodeGenContext::new(masm, stack, &frame);
-        let mut codegen =
-            CodeGen::new::<abi::X64ABI>(codegen_context, abi_sig, body, validator, regalloc);
+        let mut codegen = CodeGen::new::<abi::X64ABI>(codegen_context, abi_sig, regalloc);
 
-        codegen.emit()
+        codegen.emit(&mut body, validator)
     }
 }