macho: test empty translation units

test/link.zig

@@ -74,6 +74,10 @@ fn addMachOCases(cases: *tests.StandaloneContext) void {
         .build_modes = true,
     });
 
+    cases.addBuildFile("test/link/macho/empty/build.zig", .{
+        .build_modes = true,
+    });
+
     cases.addBuildFile("test/link/macho/entry/build.zig", .{
         .build_modes = true,
     });

test/link/macho/empty/build.zig

@@ -0,0 +1,22 @@
+const std = @import("std");
+const Builder = std.build.Builder;
+const LibExeObjectStep = std.build.LibExeObjStep;
+
+pub fn build(b: *Builder) void {
+    const mode = b.standardReleaseOptions();
+    const target: std.zig.CrossTarget = .{ .os_tag = .macos };
+
+    const test_step = b.step("test", "Test the program");
+    test_step.dependOn(b.getInstallStep());
+
+    const exe = b.addExecutable("test", null);
+    exe.addCSourceFile("main.c", &[0][]const u8{});
+    exe.addCSourceFile("empty.c", &[0][]const u8{});
+    exe.setBuildMode(mode);
+    exe.setTarget(target);
+    exe.linkLibC();
+
+    const run_cmd = exe.run();
+    run_cmd.expectStdOutEqual("Hello!\n");
+    test_step.dependOn(&run_cmd.step);
+}

test/link/macho/empty/main.c

@@ -0,0 +1,6 @@
+#include <stdio.h>
+
+int main(int argc, char* argv[]) {
+  printf("Hello!\n");
+  return 0;
+}