feat(ops): fast calls for Wasm (#16776)

This PR introduces Wasm ops. These calls are optimized for entry from
Wasm land.

The `#[op(wasm)]` attribute is opt-in. 

Last parameter `Option<&mut [u8]>` is the memory slice of the Wasm
module *when entered from a Fast API call*. Otherwise, the user is
expected to implement logic to obtain the memory if `None`

```rust
#[op(wasm)]
pub fn op_args_get(
  offset: i32,
  buffer_offset: i32,
  memory: Option<&mut [u8]>,
) {
  // ...
}
```

1 files changed, 28 insertions, 0 deletions

diff --git a/core/examples/wasm.js b/core/examples/wasm.js
new file mode 100644
index 000000000..69e475639
--- /dev/null
+++ b/core/examples/wasm.js
@@ -0,0 +1,28 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+// asc wasm.ts --exportStart --initialMemory 6400 -O -o wasm.wasm
+// deno-fmt-ignore
+const bytes = new Uint8Array([
+    0,  97, 115, 109,   1,   0,   0,   0,   1,  4,   1, 96,   0,   0,   2,
+   15,   1,   3, 111, 112, 115,   7, 111, 112, 95, 119, 97, 115, 109,   0,
+    0,   3,   3,   2,   0,   0,   5,   4,   1,  0, 128, 50,   7,  36,   4,
+    7, 111, 112,  95, 119,  97, 115, 109,   0,  0,   4, 99,  97, 108, 108,
+    0,   1,   6, 109, 101, 109, 111, 114, 121,  2,   0,  6,  95, 115, 116,
+   97, 114, 116,   0,   2,  10,  10,   2,   4,  0,  16,  0,  11,   3,   0,
+    1,  11
+ ]);
+
+const { ops } = Deno.core;
+
+const module = new WebAssembly.Module(bytes);
+const instance = new WebAssembly.Instance(module, { ops });
+ops.op_set_wasm_mem(instance.exports.memory);
+
+instance.exports.call();
+
+const memory = instance.exports.memory;
+const view = new Uint8Array(memory.buffer);
+
+if (view[0] !== 69) {
+  throw new Error("Expected first byte to be 69");
+}