handle tree sitter nodes with the same starting location

[wstevick]

I have discovered that often, two nodes have the same starting location. This happens when one is the first child of the other. For instance, ```lua
local function something()
if sometest() then
function_in_if()
end
other_function()
end

If you're cursor is on `function_in_if`, there's not way to select just the if-block without selecting the entire function body.

[ggandor]

Yes, I don't think this can be solved in a satisfying way. See also mfussenegger/nvim-treehopper#23 (comment), and the whole discussion above/below.

[wstevick]

Okay. Thanks anyway.