fix(to_cpp1): define type-scope object alias with wildcard type inline

[JohelEGP]

trafficstars

Resolves #700. Resolves #842. Resolves #1221.

[JohelEGP]

evens_doubled: @struct type = {
  filter :== :(x: int) x % 2 == 0;
  map    :== :(x: int) x * 2;
}

currently emits to

/home/johel/tmp/Waarudo/ClangDebug/sources/main.cpp:23:42: error: expected expression
   23 |   public: static constexpr auto filter = public: [](cpp2::in<int> x) -> auto { return x % 2 == 0; };
      |                                          ^
/home/johel/tmp/Waarudo/ClangDebug/sources/main.cpp:23:33: error: declaration of variable 'filter' with deduced type 'const auto' requires an initializer
   23 |   public: static constexpr auto filter = public: [](cpp2::in<int> x) -> auto { return x % 2 == 0; };
      |                                 ^
/home/johel/tmp/Waarudo/ClangDebug/sources/main.cpp:24:39: error: expected expression
   24 |   public: static constexpr auto map = public: [](cpp2::in<int> x) -> auto { return x * 2; };
      |                                       ^
/home/johel/tmp/Waarudo/ClangDebug/sources/main.cpp:24:33: error: declaration of variable 'map' with deduced type 'const auto' requires an initializer
   24 |   public: static constexpr auto map = public: [](cpp2::in<int> x) -> auto { return x * 2; };
      |                                 ^
4 errors generated.

[JohelEGP]

Commit a7ab29e0930a076655730b048b6d3f8faf867544 added a test I need to uncomment: https://github.com/hsutter/cppfront/commit/a7ab29e0930a076655730b048b6d3f8faf867544?diff=unified&w=1#diff-ae13b6b6670a9a734209e2ebb439bc244d45ad614d07206ef68545ed713f025aR15-R18.