feat: export translated C headers as a public Zig module

.github/workflows/ci.yml

@@ -40,3 +40,6 @@ jobs:
 
       - name: zig build (Release Safe)
         run: zig build --release=safe
+
+      - name: zig build test (Release Safe)
+        run: zig build test --release=safe

README.md

@@ -12,5 +12,14 @@ const blst_dep = b.dependency("blst", .{
     .optimize = optimize,
 });
 
-your_exe.linkLibrary(blst_dep.artifact("blst"));
+your_exe.root_module.addImport("blst", blst_dep.module("blst"));
+```
+
+The module contains the translated declarations from `blst.h` and
+`blst_aux.h`, and links the native library automatically:
+
+```zig
+const blst = @import("blst");
+
+const generator = blst.blst_p1_generator();
 ```

build.zig

@@ -67,5 +67,29 @@ pub fn build(b: *std.Build) !void {
         .flags = c_flags.items,
     });
 
+    const translated_headers = b.addTranslateC(.{
+        .root_source_file = upstream.path("bindings/blst.h"),
+        .target = target,
+        .optimize = optimize,
+    });
+    translated_headers.addIncludePath(upstream.path("bindings"));
+
+    const module = translated_headers.addModule("blst");
+    module.linkLibrary(lib);
+
     b.installArtifact(lib);
+
+    const module_tests = b.addTest(.{
+        .name = "blst-module-tests",
+        .root_module = b.createModule(.{
+            .root_source_file = b.path("src/test.zig"),
+            .target = target,
+            .optimize = optimize,
+        }),
+    });
+    module_tests.root_module.addImport("blst", module);
+
+    const run_module_tests = b.addRunArtifact(module_tests);
+    const test_step = b.step("test", "Test the public blst module");
+    test_step.dependOn(&run_module_tests.step);
 }

src/test.zig

@@ -0,0 +1,7 @@
+const std = @import("std");
+const blst = @import("blst");
+
+test "translated core and auxiliary APIs are linked" {
+    try std.testing.expect(blst.blst_p1_generator() != null);
+    try std.testing.expectEqual(@sizeOf(blst.blst_p1), blst.blst_p1_sizeof());
+}