Don't walk text/labels when mirroring

We have a fixed bottom-align for the text and labels in eeschema.
Therefore, mirroring vertically needs to account for the text's offset
from the bounding box center.

Fixes https://gitlab.com/kicad/code/kicad/issues/9208

eeschema/tools/sch_edit_tool.cpp

@@ -792,6 +792,21 @@ int SCH_EDIT_TOOL::Mirror( const TOOL_EVENT& aEvent )
                         pin->MirrorHorizontally( sheet->GetBoundingBox().GetCenter().x );
                 }
             }
+            else if( item->Type() == SCH_TEXT_T || item->Type() == SCH_LABEL_T )
+            {
+                /// Text and Labels are aligned to their bottom right corners and we don't flip the
+                /// alignment corner, so we need to offset this in the vertical direction
+
+                wxPoint textMirrorPoint = mirrorPoint;
+
+                textMirrorPoint.y += item->GetBoundingBox().GetHeight() / 2;
+                textMirrorPoint = m_frame->GetNearestHalfGridPosition( textMirrorPoint );
+
+                if( vertical )
+                    item->MirrorVertically( textMirrorPoint.y );
+                else
+                    item->MirrorHorizontally( textMirrorPoint.x );
+            }
             else
             {
                 if( vertical )