dmd.ies.dd

Add support for Interpolated Expression Sequences

Interpolated Expression Sequences are a way to implement things like string interpolation in library code. Three forms of literals are added:

```
i"Content $(a + 4)"
i`Content $(a + 4)`
iq{Content $(a + 4)}
```

all provide the same thing: a tuple that can be passed to other functions, like `writeln` from `std.stdio` and `text` from `std.conv`:

```
int a = 6;
writeln(i"Content $(a + 4)"); // prints "Content 10"
```

You can also pass them to other functions which understand the types in the new `core.interpolation` module. Numerous examples can be found documentation of that module or in this repository: https://github.com/adamdruppe/interpolation-examples/