adding llvm build option

build.zig

@@ -4,6 +4,8 @@ pub fn build(b: *std.Build) void {
     const target = b.standardTargetOptions(.{});
     const optimize = b.standardOptimizeOption(.{});
 
+    const use_llvm = b.option(bool, "use-llvm", "LLVM build") orelse (b.release_mode != .off);
+
     const miclib_include = b.option(
         []const u8,
         "miclib_include",
@@ -47,7 +49,10 @@ pub fn build(b: *std.Build) void {
 
     module.addImport("miclib_c", c_includes.createModule());
 
-    const lib_tests = b.addTest(.{ .root_module = test_module });
+    const lib_tests = b.addTest(.{
+        .root_module = test_module,
+        .use_llvm = use_llvm,
+    });
     const run_tests = b.addRunArtifact(lib_tests);
     const test_step = b.step("test", "Run unit tests");
     test_step.dependOn(&run_tests.step);
@@ -62,6 +67,7 @@ pub fn build(b: *std.Build) void {
     const enumerate = b.addExecutable(.{
         .name = "miclib-enumerate",
         .root_module = enumerate_module,
+        .use_llvm = use_llvm,
     });
 
     b.installArtifact(enumerate);