Unused/obsolete code in XtermEngine

[j4james]

In the XtermEngine::StartPaint method, there's some code that calculates the dirty area here:

terminal/src/renderer/vt/XtermEngine.cpp

Lines 85 to 97 in 183a895

	{
	std::span<const til::rect> dirty;
	RETURN_IF_FAILED(GetDirtyArea(dirty));
	// If we have 0 or 1 dirty pieces in the area, set as appropriate.
	auto dirtyView = dirty.empty() ? Viewport::Empty() : Viewport::FromExclusive(til::at(dirty, 0));
	// If there's more than 1, union them all up with the 1 we already have.
	for (size_t i = 1; i < dirty.size(); ++i)
	{
	dirtyView = Viewport::Union(dirtyView, Viewport::FromExclusive(til::at(dirty, i)));
	}
	}

However, the result of that calculation is not actually used. There was a time when there was more code in that branch that compared the dirty area against the last viewport, but that was removed in PR #4741.

---

And in the XtermEngine::_MoveCursor method there's a local variable performedSoftWrap which is initially set to false at the start of the method here:

terminal/src/renderer/vt/XtermEngine.cpp

Line 249 in 183a895

auto performedSoftWrap = false;

And it's potentially changed to true later in the code:

terminal/src/renderer/vt/XtermEngine.cpp

Lines 273 to 278 in 183a895

	if (previousLineWrapped)
	{
	performedSoftWrap = true;
	_trace.TraceWrapped();
	hr = S_OK;
	}

However, the variable is otherwise never read. It looks like it was added as part of PR #5181, but even then it doesn't appear to have been used.

Unless there is something I'm missing, I'd suggest we should remove the unused code.

[DHowett]

I'm alright removing it!