Enable the multi-value proposal by default (#1667)

This was merged into the wasm spec upstream in WebAssembly/spec#1145, so
let's follow the spec and enable it by default here as well!

crates/api/src/runtime.rs

@@ -82,7 +82,7 @@ impl Config {
                     enable_reference_types: false,
                     enable_bulk_memory: false,
                     enable_simd: false,
-                    enable_multi_value: false,
+                    enable_multi_value: true,
                 },
             },
             flags,
@@ -247,16 +247,10 @@ impl Config {
     /// Configures whether the WebAssembly multi-value proposal will
     /// be enabled for compilation.
     ///
-    /// The [WebAssembly multi-value proposal][proposal] is not
-    /// currently fully standardized and is undergoing development.
-    /// Additionally the support in wasmtime itself is still being worked on.
-    /// Support for this feature can be enabled through this method for
-    /// appropriate wasm modules.
-    ///
     /// This feature gates functions and blocks returning multiple values in a
     /// module, for example.
     ///
-    /// This is `false` by default.
+    /// This is `true` by default.
     ///
     /// [proposal]: https://github.com/webassembly/multi-value
     pub fn wasm_multi_value(&mut self, enable: bool) -> &mut Self {

crates/fuzzing/src/lib.rs

@@ -39,7 +39,6 @@ pub(crate) fn fuzz_default_config(
     config
         .cranelift_debug_verifier(true)
         .cranelift_nan_canonicalization(true)
-        .wasm_multi_value(true)
         .wasm_bulk_memory(true)
         .strategy(strategy)?;
     Ok(config)

crates/misc/rust/macro/src/lib.rs

@@ -53,8 +53,7 @@ fn generate_load(item: &syn::ItemTrait) -> syn::Result<TokenStream> {
             use #root::wasmtime::{Config, Extern, Engine, Store, Instance, Module};
             use #root::anyhow::{bail, format_err};
 
-            let engine = Engine::new(Config::new().wasm_multi_value(true));
-            let store = Store::new(&engine);
+            let store = Store::default();
 
             let data = #root::wasmtime_interface_types::ModuleData::new(bytes.as_ref())?;
 

crates/wast/src/wast.rs

@@ -356,6 +356,8 @@ fn is_matching_assert_invalid_error_message(expected: &str, actual: &str) -> boo
         // `elem.wast` and `proposals/bulk-memory-operations/elem.wast` disagree
         // on the expected error message for the same error.
         || (expected.contains("out of bounds") && actual.contains("does not fit"))
+        // slight difference in error messages
+        || (expected.contains("unknown elem segment") && actual.contains("unknown element segment"))
 }
 
 fn extract_lane_as_i8(bytes: u128, lane: usize) -> i8 {