VB -> C#: String comparison doesn't follow VB's special logic after conversion

[GrahamTheCoder]

Input code

    Dim x = ""
    Dim y = Nothing
    Dim z = x = y

Erroneous output

    var x = "";
    var y = null;
    var z = x == y;

Expected output

    var x = "";
    var y = null;
    var z = (x ?? "") == (y ?? "");

Details

Product in use: both

Version in use: 5.6.3

String operators = and <> should be converted to things that treat null and "" as equal.

• x = y -> Microsoft.VisualBasic.CompilerServices.Operators.CompareString(string, string, bool) == 0
  *x <> y -> Microsoft.VisualBasic.CompilerServices.Operators.CompareString(string, string, bool) != 0
• Comparison with empty string literal -> string.IsNullOrEmpty

CodeConverter/TestData/SelfVerifyingTests/VBToCS/ExpressionTests.vb

Lines 21 to 26 in dd45721

	<Fact(Skip := "https://github.com/icsharpcode/CodeConverter/issues/105")>
	Public Sub EmptyStringEqualityToNull()
	Dim s As String = ""
	Dim areEqual As Boolean = s = Nothing
	Assert.True(areEqual)
	End Sub

should be enabled when this issue is resolved

[GrahamTheCoder]

#317 covered this