EnC: Moving a method with a parameter across partial definitions issues wrong rude edit

[davidwengier]

Version Used:
Version 16.10.0 Preview 2.0 [31128.4.main]

Steps to Reproduce:

Before edit:

File 1:

partial class C
{
   void F2() {}
}

File 2:

partial class C
{
   void F2(int a) {}
}

After edit:

File 1:

partial class C
{
   void F2(int a) {}
}

File 2:

partial class C
{
   void F2() {}
}

Expected Behavior:

Each document has semantic update of F2, respectively.

Actual Behavior:

"Add parameter" rude edit is reported.

[davidwengier]

FYI @tmat, not sure if you want to just consider this another part of #51011