imenu: show static member variable instead of function

[vohv]

When I use imenu, emacs displays the static member variables of the function instead of the function.
only lsp-mode + emacs-ccls has this problem.

I tried the following schemes are all good:

• lsp-mode + clangd
• eglot + clangd
• eglot + ccls

I don't know if this is the problem of lsp-mode or emacs-ccls.

If my function has many static member variables, positioning the function will become very difficult.