added initial support for the Coccinelle code transformation system, closes #6999 (#7001)

This fork provides a rudimentary way of using Coccinelle within Compiler
Explorer.
In the left window one can edit either C or C++ code, and within
preprocessor ifdefs, one can write a semantic patch for Coccinelle.
The right window will display the transformed code.

A coccinelle on infra is not yet done.
Any distribution-based coccinelle would do, for the moment.

If you like it, this close #6999 .

---------

Signed-off-by: Michele Martone <michelemartone@users.sourceforge.net>
Co-authored-by: Patrick Quist <partouf@gmail.com>
Co-authored-by: Mats Jun Larsen <mats@jun.codes>
Co-authored-by: Matt Godbolt <matt@godbolt.org>

types/languages.interfaces.ts

@@ -39,6 +39,8 @@ export type LanguageKey =
     | 'cmake'
     | 'cmakescript'
     | 'cobol'
+    | 'coccinelle_for_c'
+    | 'coccinelle_for_cpp'
     | 'cpp_for_opencl'
     | 'cppx'
     | 'snowball'