Compile polkadot-runtime both for Wasm ad native, allowing for testing and direct usage.

substrate/wasm-runtime/pwasm-alloc/src/lib.rs

@@ -0,0 +1,30 @@
+#![warn(missing_docs)]
+#![cfg_attr(feature = "strict", deny(warnings))]
+#![no_std]
+#![crate_type = "rlib"]
+#![feature(global_allocator)]
+#![feature(alloc)]
+#![feature(allocator_api)]
+
+//! Custom allocator crate for wasm
+
+extern crate alloc;
+extern crate pwasm_libc;
+
+use alloc::heap::{Alloc, Layout, AllocErr};
+
+/// Wasm allocator
+pub struct WasmAllocator;
+
+unsafe impl<'a> Alloc for &'a WasmAllocator {
+	unsafe fn alloc(&mut self, layout: Layout) -> Result<*mut u8, AllocErr> {
+		Ok(pwasm_libc::malloc(layout.size()))
+	}
+
+	unsafe fn dealloc(&mut self, ptr: *mut u8, _layout: Layout) {
+		pwasm_libc::free(ptr)
+	}
+}
+
+#[global_allocator]
+static ALLOCATOR: WasmAllocator = WasmAllocator;