Companion: wasm-builder support stable Rust (#6967)

* Companion: wasm-builder support stable Rust

* update lockfile for {"substrate"}

---------

Co-authored-by: parity-processbot <>

polkadot/parachain/test-parachains/halt/build.rs

@@ -17,5 +17,17 @@
 use substrate_wasm_builder::WasmBuilder;
 
 fn main() {
-	WasmBuilder::new().with_current_project().export_heap_base().build()
+	WasmBuilder::new().with_current_project().export_heap_base().build();
+
+	enable_alloc_error_handler();
 }
+
+#[rustversion::before(1.68)]
+fn enable_alloc_error_handler() {
+	if !cfg!(feature = "std") {
+		println!("cargo:rustc-cfg=enable_alloc_error_handler");
+	}
+}
+
+#[rustversion::since(1.68)]
+fn enable_alloc_error_handler() {}