Create a generator for `EmbeddedBuiltinDefinitions.cpp`

[tapple]

This C file is where slua gets its globals. slua-analyze won't work without it unless it grows support for d.luau files sometime soon

There's 2 places that would be really nice to typecheck, where including luau-lsp would be vastly overkill:

• slua playground https://slua-playground.wlf.io/
• the secondlife viewer

But, this is impractical without a generator for EmbeddedBuiltinDefinitions.cpp

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One other benefit of embedding the slua definitions has to do with the magic type functions. The short version: due to the order in which luau-lsp reads the definitions, luau-lsp is unable to use the best available typechecker logic for the functions table.freeze, table.clone, and table.pack. For the long version, see these comments, and the whole PR they are in:

• secondlife.d.luau shadows the table magic functions
• table.freeze magic function
• table.clone magic function
• table.pack magic function

[CatfishW]

/try

Plan:

• add a real EmbeddedBuiltinDefinitions.cpp generator path instead of another partial helper
• generate the full builtin source from both the Luau builtin section and the SLua/library section in slua_definitions.yaml
• emit a drop-in C++ file via a template, wire it into gen_all_definitions.sh, and add the generated output under generated/cpp/ for verification
• keep the existing slua_lsp_defs output stable while adding the new generator

[opirebot]

😅 Ups... this issue does not have any reward yet!