HXCPP: incorrect use of ->

problem: using array access to get a Vec4 from a Matrix class and calling any of its fields `mat[0].x` replaces it with `mat.columns[0]->x`, expected until the `->` part, my set up is
```
struct Vec4 {
union {
struct { double x, y, z, w;};
double v[4];
};

};

struct Mat4 {
union {
struct { Vec4 col0, col1, col2, col3; };
Vec4 columns[4];
double v[16];
};

};
```
and the natives on the Haxe side already have `@:structAccess`, what's important is the `@:arrayAccess` functions:

Vec4:
```
@:arrayAccess inline private function getAt(index:Int):Ref { return untyped __cpp__("{0}.v[{1}]", this, index); }
@:arrayAccess inline private function setAt(index:Int, v:Float):Ref { return untyped __cpp__("{0}.v[{1}] = {2}", this, index, v); }
```
Mat4:
```
@:arrayAccess inline private function getAt(index:Int):Vec4 { return untyped __cpp__("{0}.columns[{1}]", this, index); }
@:arrayAccess inline private function setAt(index:Int, v:Vec4):Vec4 { return untyped __cpp__("{0}.columns[{1}] = {2}", this, index, v); }
```

it should always use a dot instead of `->` when accessing a Vec4 instance, like in these examples:
`vec.x` in Haxe becomes `vec.x` in C++
`vec[0]` becomes `vec.v[0]`
`var vec = mat[0];` becomes `Vec4 & vec1 = mat.columns[0];`
`mat[0][1]` becomes `Vec4 & this7 = mat.columns[0]; this7.v[1];`
but as soon as i try to access a Vec4 field directly from Mat4 like `mat[0].x` it uses `->` instead `mat.columns[0]->x`

after a bit of testing, i found out that this happens fields/methods that are specifically defined in C++, so extern inlined function or fields on the Haxe side dont get affected as they just get pasted