Fix deconstruct and fully qualified types in async foreach

[GerardSmit]

This PR fixes 2 bugs with await foreach that I encountered:

Deconstruct

Source

[CreateSyncVersion]
async Task<int> SumAsync(IAsyncEnumerable<(int a, int b)> enumerable)
{
    int sum = 0;

    await foreach (var (a, b) in enumerable)
    {
        sum += a + b;
    }

    return sum;
}

Before

await wasn't being removed from the foreach:

int Sum(global::System.Collections.Generic.IEnumerable<(int a, int b)> enumerable)
{
    int sum = 0;

    await foreach (var (a, b) in enumerable)
    {
        sum += a + b;
    }

    return sum;
}

After

int Sum(global::System.Collections.Generic.IEnumerable<(int a, int b)> enumerable)
{
    int sum = 0;

    foreach (var (a, b) in enumerable)
    {
        sum += a + b;
    }

    return sum;
}

Fully quallified type

Source

[CreateSyncVersion]
async Task<int> SumAsync(IAsyncEnumerable<int?> enumerable)
{
    int sum = 0;

    await foreach (int? i in enumerable)
    {
        if (i.HasValue)
        {
            sum += i.Value;
        }
    }
    
    return sum;
}

Before

await wasn't being removed from the foreach:

int Sum(global::System.Collections.Generic.IEnumerable<int?> enumerable)
{
    int sum = 0;

    await foreach (int? i in enumerable)
    {
        if (i.HasValue)
        {
            sum += i.Value;
        }
    }
    
    return sum;
}

After

int Sum(global::System.Collections.Generic.IEnumerable<int?> enumerable)
{
    int sum = 0;

    foreach (int? i in enumerable)
    {
        if (i.HasValue)
        {
            sum += i.Value;
        }
    }

    return sum;
}

[GerardSmit]

I had a fight with the new line endings check, so I moved the tests to an already existing file.. 😅

[virzak]

Thanks so much for the PR, @GerardSmit .

Version 1.3.38 has the changes.