Adding ANSI C11 C compiler to D so it can import and compile C files directly
Adding the ability to just read header files and all the definitions in them without having to translate.I saw this addition in zig and thought that it was amazing, a lot of languages have this need to create definitions in their own language, C# with [DllImport](https://docs.microsoft.com/en-us/dotnet/api/system.runtime.i...), [crystal with lib](https://crystal-lang.org/reference/syntax_and_semantics/c_bi...), I think since C is so ubiquitous and being able to just consume header files just removes so much boilerplate creation that is easy to get wrong.zig also decided to just call an existing compiler (clang) and if you do zig cc --version then zig thinks it is clang, because the zig compiler just calls into clang main. D has gone with the route of calling gcc.