add cmake for llvm

packages/l/llvm/xmake.lua

@@ -51,6 +51,7 @@ package("llvm")
         if linuxos.name() == "ubuntu" and linuxos.version():eq("20.04") and os.arch() == "x86_64" then
             -- use binary directly
         else
+            add_deps("cmake")
             add_deps("libffi", {host = true})
             add_deps("binutils", {host = true}) -- needed for gold and strip
         end