preprocessor define option

Motivation and Context

closes #1060 (closed)

Description

simply pass the -D preprocessor option to the frontend

Component

• compiler
• website
• webide
• vscode-plugin
• debugger

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Performance improvement (non-breaking change that improves performance)
• None (change with no changelog)

Changelog

You can now pass a list of defines to LIGO preprocessor using flag -D.

(* myfile.mligo *)
#if FOO
[@entry] let toto () () : operation list * unit = failwith "lol"
#endif

`ligo compile contract myfile.mligo -D FOO`

Checklist:

• If a new syntax has been introduced, put a message on slack ligo-lsp
• Changes follow the existing coding style (use dune @fmt to check).
• Tests for the changes have been added (for bug fixes / feature).
• Documentation has been updated.
• Changelog description has been added (if appropriate).
• Start titles under ## Changelog section with #### (if appropriate).
• There is no image or uploaded file in changelog
• Examples in changed behaviour have been added to the changelog (for breaking change / feature).