Unify corelib interop files with common ones #1232
Description
As an artefact of the repo merge we have files duplicated between src\libraries\Common\src\Interop and src\libraries\System.Private.CoreLib\src\Interop
The list is these (just going by file name)
Interop\Unix\Interop.Libraries.cs
Interop\Unix\System.Native\Interop.GetPid.cs
Interop\Windows\Interop.Errors.cs
Interop\Windows\Interop.Libraries.cs
Interop\Windows\Kernel32\Interop.Constants.cs
Interop\Windows\Kernel32\Interop.CreateFile.cs
Interop\Windows\Kernel32\Interop.FILE_INFO_BY_HANDLE_CLASS.cs
Interop\Windows\Kernel32\Interop.FreeLibrary.cs
Interop\Windows\Kernel32\Interop.GetCurrentProcessId.cs
Interop\Windows\Kernel32\Interop.GetFileInformationByHandleEx.cs
Interop\Windows\Kernel32\Interop.GetProcessTimes.cs
Interop\Windows\Kernel32\Interop.GlobalMemoryStatusEx.cs
Interop\Windows\Kernel32\Interop.LoadLibraryEx.cs
Interop\Windows\Kernel32\Interop.LocalAlloc.cs
Interop\Windows\Kernel32\Interop.VirtualAlloc.cs
Interop\Windows\Kernel32\Interop.VirtualQuery.cs
Interop\Windows\NtDll\Interop.NtQuerySystemInformation.cs
Interop\Windows\User32\Interop.Constants.cs
Interop\Windows\User32\Interop.SendMessageTimeout.cs
In each case we should verify the content is the same (or unify it) then delete the System.Private.CoreLib copies in favor of the common ones, updating src\libraries\System.Private.CoreLib\src\System.Private.CoreLib.Shared.projitems and src\coreclr\src\System.Private.CoreLib\System.Private.CoreLib.csproj to match
@jkotas I thought we had a work item for unifying interop stuff but I couldn't find it. Maybe it was already complete and this is another.