wasm 0.5.0

Run WebAssembly binaries in PHP

WebAssembly (abbreviated Wasm) is a binary instruction format for
a stack-based virtual machine. Wasm is designed as a portable target
for compilation of high-level languages like C/C++/Rust, enabling
deployment on the web for client and server applications.

This extension allows to run Wasm binaries inside PHP.

License: MIT

Changes

# Features

## Extension

* #71 Use pre-build dynamic libraries (@Hywan)
* #70 Improve function invocation time by 77% (@Hywan)
* #69 Introduce the `wasm_instance` structure (@Hywan)
* #68 Add the `WasmArrayBuffer::grow` method (@Hywan)

## Runtime

* #72 Update Wasmer to 0.5.5 (@Hywan)

# Bug/security fixes

* #67 Update smallvec (@Hywan)
* #48 Fix the extension compilation on CentOS (@Hywan)

# Documentation

* Many improvements related to the new features and bug fixes.

# Chore

* #59 Tweak Bors (@Hywan)