add cgo example; fix zig url

BUILD

@@ -0,0 +1,7 @@
+load("@bazel_gazelle//:def.bzl", "gazelle")
+load("@com_github_bazelbuild_buildtools//buildifier:def.bzl", "buildifier")
+
+# gazelle:build_file_name BUILD
+gazelle(name = "gazelle")
+
+buildifier(name = "buildifier")

test/BUILD

@@ -11,3 +11,5 @@ cc_binary(
     name = "exception",
     srcs = ["exception.cpp"],
 )
+
+# go build -ldflags "-linkmode external -extldflags -static" hello.go

test/hello.go

@@ -0,0 +1,9 @@
+package main
+
+// #include <stdio.h>
+// void helloworld() { printf("hello, world\n"); }
+import "C"
+
+func main() {
+	C.helloworld()
+}

zig-toolchains/defs.bzl

@@ -82,7 +82,7 @@ def toolchain_repositories():
         name = "com_github_ziglang_zig",
 
         version = "0.8.0",
-        url_format = "https://ziglang.org/builds/zig-{host_platform}-{version}.tar.xz",
+        url_format = "https://ziglang.org/download/{version}/zig-{host_platform}-{version}.tar.xz",
         host_platform_sha256 = {
             "linux-x86_64": "502625d3da3ae595c5f44a809a87714320b7a40e6dff4a895b5fa7df3391d01e",
             "macos-x86_64": "279f9360b5cb23103f0395dc4d3d0d30626e699b1b4be55e98fd985b62bc6fbe",