Add the Go bindings build script

scripts/uniffi_bindgen_generate_go.sh

@@ -0,0 +1,35 @@
+#!/bin/bash
+
+set -e
+
+if ! command -v cross &> /dev/null; then
+  echo "cross-rs is required to build bindings. Install it by running:"
+  echo "  cargo install cross --git https://github.com/cross-rs/cross"
+  exit 1
+fi
+
+uniffi-bindgen-go bindings/ldk_node.udl -o ffi/golang -c ./uniffi.toml
+
+build_lib() {
+  local TOOL=$1
+  local TARGET=$2
+  local OUTPUT_FILE=$3
+
+  $TOOL build --release --target $TARGET --features uniffi || exit 1
+  mkdir -p "ffi/golang/ldk_node/$TARGET" || exit 1
+  cp "target/$TARGET/release/$OUTPUT_FILE" "ffi/golang/ldk_node/$TARGET/" || exit 1
+}
+
+is_target_installed() {
+  local TARGET=$1
+  rustup target list --installed | grep -q $TARGET
+}
+
+# If we're running on macOS, build the macOS library using the host compiler.
+# Cross compilation is not supported (needs more complex setup).
+if [[ "$OSTYPE" == "darwin"* ]]; then
+  build_lib "cargo" "aarch64-apple-darwin" "libldk_node.dylib"
+fi
+
+build_lib "cross" "x86_64-unknown-linux-gnu" "libldk_node.so"
+build_lib "cross" "x86_64-pc-windows-gnu" "ldk_node.dll"