Lua Parsing of Tracepoint Fields doesn't handle `__data_loc` correctly

Some arguments of tracepoint fields are of the format `__data_loc char[] var,` which is not being parsed correctly by the Lua tooling.

This problem is very similar to the one mentioned here: https://github.com/bpftrace/bpftrace/issues/385

To fix this, I have taken the same approach proposed by @brendangregg in that issue of transforming them to `char*` instead.

`src/lua/bpf/cdef.lua`:
```
275,276c275
< local g = string.gsub(f, "__data_loc char%[%]", "char*")
< table.insert(fields, g)
---
> table.insert(fields, f)
```

My approach right now is rather a hack, so please advise on what should be done.

Read src/lua/bpf/cdef.lua around lines 275-276 and trace how tracepoint field strings reach the fields list. Reproduce a __data_loc char[] var field through the Lua tooling, then verify that parsing produces the intended char* representation without breaking other field forms.

Written by the indexing model from the issue text.