Add LLVM option to Sciter and then give up

packages/sciter/build.zig

@@ -26,6 +26,7 @@ pub fn build(b: *std.Build) void {
         },
     });
     const optimize = b.standardOptimizeOption(.{});
+    const llvm = b.option(bool, "llvm", "Use LLVM and LLD") orelse false;
 
     const exe_mod = b.createModule(.{
         .root_source_file = b.path("src/main.zig"),
@@ -36,6 +37,8 @@ pub fn build(b: *std.Build) void {
     const exe = b.addExecutable(.{
         .name = "sciter",
         .root_module = exe_mod,
+        .use_llvm = llvm,
+        .use_lld = llvm,
     });
 
     b.installArtifact(exe);