Clear some compile warnings

eeschema/dialogs/dialog_spice_model.cpp

@@ -804,9 +804,11 @@ bool DIALOG_SPICE_MODEL::addPwlValue( const wxString& aTime, const wxString& aVa
     float timeF;
     m_pwlTime->GetValue().ToDouble( &timeD );
     timeF = timeD;
+    long data;
+    std::memcpy( &data, &timeF, sizeof( timeF ) );
 
     // Store the time value, so the entries can be sorted
-    m_pwlValList->SetItemData( idx, *reinterpret_cast<long*>( &timeF ) );
+    m_pwlValList->SetItemData( idx, data );
 
     // Sort items by timestamp
     m_pwlValList->SortItems( comparePwlValues, -1 );

pcbnew/load_select_footprint.cpp

@@ -496,8 +496,6 @@ void PCB_BASE_FRAME::PlaceModule( MODULE* aModule, bool aRecreateRatsnest )
         s_PickedList.ClearItemsList();
     }
 
-    auto displ_opts = (PCB_DISPLAY_OPTIONS*)GetDisplayOptions();
-
     aModule->SetPosition( (wxPoint) GetCanvas()->GetViewControls()->GetCursorPosition() );
     aModule->ClearFlags();
 

polygon/clipper.cpp

@@ -889,7 +889,8 @@ void DisposeOutPts( OutPt*& pp )
 
 inline void InitEdge( TEdge* e, TEdge* eNext, TEdge* ePrev, const IntPoint& Pt )
 {
-    std::memset( e, 0, sizeof(TEdge) );
+    // This clears the C++ way
+    *e = TEdge( { 0 } );
 
     e->Next = eNext;
     e->Prev = ePrev;