[SR-9336] importing structures with anonymous fields crashes the ClangImporter

[compnerd]

Previous ID	SR-9336
Radar	None
Original Reporter	@compnerd
Type	Improvement

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Improvement, Android, ClangImporter, Linux, StarterBug, Windows
Assignee	None
Priority	Medium

md5: e340d6800850b57905470aa79f4a8815

Issue Description:

Seems that the typo correction on windows asserts trying to create an anonymous field accessor. This occurred at least in Data.swift in swift-corelibs-foundation trying to typo correct munmap.

[belkadan]

I bet this reproduces on other platforms if you can figure out what it was trying to import.

[compnerd]

This is due to the use of anonymous fields in structures which Microsoft uses extensively in the Windows SDK. Something like this does the trick:

```
import WinSDK
_ = htont()
```

[finagolfin]

@stevapple, still a problem on Windows? Please close if not.