Well-known metadata not available when dynamically creating items

Well-known item metadata is not available during item creation for dynamically defined items (items defined within a Target). I am not super familiar with msbuild but this was surprising to me.

### Steps to reproduce

Project file
```xml

```

Directory contents:
```
/
- repro.proj
- myfiles/
- file1
- file2
- file3
```

Command line
```
msbuild repro.proj /t:MyTarget
```
### Expected behavior
Prints:
```
myfiles\file1 -> file1
myfiles\file2 -> file2
myfiles\file3 -> file3
myfiles\file1 -> file1
myfiles\file2 -> file2
myfiles\file3 -> file3
myfiles\file1 -> file1
myfiles\file2 -> file2
myfiles\file3 -> file3
```

### Actual behavior
Prints:
```
myfiles\file1 -> file1
myfiles\file2 -> file2
myfiles\file3 -> file3
myfiles\file1 ->
myfiles\file2 ->
myfiles\file3 ->
myfiles\file1 -> file1
myfiles\file2 -> file2
myfiles\file3 -> file3
```

### Environment data
`msbuild /version` output:

```
Microsoft (R) Build Engine version 15.4.8.50001 for .NET Framework
Copyright (C) Microsoft Corporation. All rights reserved.

15.4.8.50001
```

OS info:
`Microsoft Windows [Version 10.0.16299.192]`

If applicable, version of the tool that invokes MSBuild (Visual Studio, dotnet CLI, etc):

I'm seeing this behavior everywhere - VS, dotnet, running msbuild manually.