Update README

README.md

@@ -41,3 +41,8 @@ To test the `ADDITIONAL_ARGUMENTS` locally, we can run `ckb-debugger --bin ./bui
 - `-e` is used to evaluate some lua script. For example, running `ckb-debugger --bin ./build/lua-loader.debug -- -e 'print("abcdefg")'` will print out `abcdefg` in to console.
 - `-f` is used to enable [file system access](./docs/fs.md). For example, running `ckb-debugger --bin ./build/lua-loader.debug -- -f` would evaluate the `main.lua` file within the file system in the cell data.
 - `-r` is used to execute coded loaded from ckb-debugger. For example, running `ckb-debugger ---read-file strings.lua --bin ./build/lua-loader.debug -- -r` will execute the lua file `strings.lua`. Normally, ckb-lua-vm can not read files from local file system, we add this parameter (along with the `--read-file` parameter of `ckb-debugger`) to facilitate testing of running local lua files.
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+## LLVM & GCC
+The project uses LLVM for compilation by default but also supports GCC (via `Makefile.gcc`).
+However, please note that LLVM does not support dynamic libraries, so GCC must be used in such cases.