winch: Handle -W tail-call (#8447)

Fixes #8446

The WebAssembly tail call proposal is currently not supported in Winch. This commit returns an error when trying to enable the tail call proposal while using Winch as the compiler. 

Even though the issue linked above doesn't make use of any of the tail instructions, the trampolines were generated using Cranelift's tail call calling convention.

crates/cranelift/src/lib.rs

@@ -228,6 +228,12 @@ fn wasm_call_signature(
                 Architecture::S390x,
                 "https://github.com/bytecodealliance/wasmtime/issues/6530"
             );
+
+            assert!(
+                !tunables.winch_callable,
+                "Winch doesn't support the WebAssembly tail call proposal",
+            );
+
             CallConv::Tail
         }
 

crates/wasmtime/src/config.rs

@@ -1755,11 +1755,16 @@ impl Config {
                 Strategy::Cranelift => false,
                 Strategy::Winch => true,
             };
+
+            if tunables.winch_callable && tunables.tail_callable {
+                bail!("Winch does not support the WebAssembly tail call proposal");
+            }
         }
 
         if tunables.static_memory_offset_guard_size < tunables.dynamic_memory_offset_guard_size {
             bail!("static memory guard size cannot be smaller than dynamic memory guard size");
         }
+
         Ok(tunables)
     }