Use nint for native-sized integers in Marshal

[xtqqczze]

Related: dotnet/runtime#118335

cc: @jkotas

[jkotas]

This is the first place that where MemberSignature Language="C#" uses nint instead IntPtr in this repo. @gewarren Are there any non-obvious consequences?

[xtqqczze]

This is the first place that where MemberSignature Language="C#" uses nint instead IntPtr in this repo. @gewarren Are there any non-obvious consequences?

nint is used for Math.Abs, but with a FrameworkAlternate attribute. Since nint/nuint become full aliases to IntPtr/UIntPtr in .NET 7 this suggests there could be consequences.

dotnet-api-docs/xml/System/Math.xml

Lines 463 to 469 in 369ed46

	<MemberSignature Language="C#" Value="public static IntPtr Abs (IntPtr value);" FrameworkAlternate="net-10.0;net-7.0;net-8.0;net-9.0" />
	<MemberSignature Language="ILAsm" Value=".method public static hidebysig native int Abs(native int value) cil managed" />
	<MemberSignature Language="DocId" Value="M:System.Math.Abs(System.IntPtr)" />
	<MemberSignature Language="VB.NET" Value="Public Shared Function Abs (value As IntPtr) As IntPtr" />
	<MemberSignature Language="F#" Value="static member Abs : nativeint -&gt; nativeint" Usage="System.Math.Abs value" />
	<MemberSignature Language="C++ CLI" Value="public:&#xA; static IntPtr Abs(IntPtr value);" />
	<MemberSignature Language="C#" Value="public static nint Abs (nint value);" FrameworkAlternate="net-6.0" />

[gewarren]

This is the first place that where MemberSignature Language="C#" uses nint instead IntPtr in this repo. @gewarren Are there any non-obvious consequences?

@jkotas The member signatures are autogenerated and will be overwritten. I'm not sure if the autogenerated signature will be the same as the change that was merged here, or if this user story (which was bulk removed in June :-( ) will prevent the proper display.