github: add buildci and its helper script

Signed-off-by: Gunwant Jain <mail@wantguns.dev>

.github/buildci.sh

@@ -0,0 +1,33 @@
+#!/bin/bash
+
+set -xe
+
+# Setup cross compiling for arm64
+setup_cross_compiling() {
+    __ARCH=$1
+
+    if [ "$__ARCH" == "arm64" ]; then
+        sudo apt update
+        sudo apt install -y gcc-aarch64-linux-gnu
+        rustup target add aarch64-unknown-linux-gnu
+    fi
+}
+
+# Building for the given architecture
+build_for_arch() {
+    __ARCH=$1
+    __SHA=$2
+
+    # Statically compile
+    case "$__ARCH" in \
+        arm64) export __TARGET='aarch64-unknown-linux-gnu' ;;
+        amd64) export __TARGET='x86_64-unknown-linux-gnu' ;;
+    esac
+
+    # Build and install
+    cargo install --target $__TARGET --path .
+
+    # Export them artifacts
+    mkdir -p artifacts
+    cp -av /home/runner/.cargo/bin/bin "artifacts/bin-$__SHA-$__TARGET"
+}