Pass linker flag to set __THUNKS permission for NativeAOT

[akoeplinger]

dotnet/runtime#82317 implemented marshalled delegate support for NativeAOT via generating thunk pages.
We need the -Wl,-segprot,__THUNKS,rx,rx linker flag to set the correct permissions on the segment.

Note: depending on how we'll integrate the NativeAOT targets into xamarin-macios this might be automatically handled, filing this just so we don't forget it if we don't use the NativeAOT targets.

[rolfbjarne]

@akoeplinger I believe we don't need to do anything here, the logic to pass these linker flags was implemented in dotnet/runtime here: dotnet/runtime@75a32b8

[filipnavara]

Yep, we can close this. As long as the linker flags are inherited from the NativeAOT logic we should be fine.