QtWidgets: Fix CMake Unity (Jumbo) builds

Remove clashing enumeration value ColumnCount and exclude
file in snippets.

Task-number: QTBUG-109394
Pick-to: 6.5
Change-Id: Ibd8a72d9d87e3dcbbb221c364d6b4c4f59b315df
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>

src/widgets/CMakeLists.txt

@@ -70,6 +70,11 @@ qt_internal_add_module(Widgets
     GENERATE_CPP_EXPORTS
 )
 
+if(APPLE)
+    set_source_files_properties(kernel/qapplication.cpp
+                                PROPERTIES SKIP_UNITY_BUILD_INCLUSION ON)
+endif()
+
 # Resources:
 set(qstyle_resource_files
     "styles/images/cdr-128.png"

src/widgets/doc/snippets/customviewstyle/CMakeLists.txt

@@ -12,3 +12,5 @@ target_link_libraries(widgets_customviewstyle_snippets PRIVATE
     Qt::Gui
     Qt::Widgets
 )
+
+set_target_properties(widgets_customviewstyle_snippets PROPERTIES UNITY_BUILD OFF)

src/widgets/kernel/qformlayout.cpp

@@ -68,8 +68,6 @@ void FixedColumnMatrix<T, NumColumns>::storageIndexToPosition(int idx, int *rowP
 const uint DefaultFieldGrowthPolicy = 255;
 const uint DefaultRowWrapPolicy = 255;
 
-enum { ColumnCount = 2 };
-
 // -- our data structure for our items
 // This owns the QLayoutItem
 struct QFormLayoutItem
@@ -152,7 +150,7 @@ class QFormLayoutPrivate : public QLayoutPrivate
     Q_DECLARE_PUBLIC(QFormLayout)
 
 public:
-    typedef QtPrivate::FixedColumnMatrix<QFormLayoutItem *, ColumnCount> ItemMatrix;
+    using ItemMatrix = QtPrivate::FixedColumnMatrix<QFormLayoutItem *, 2>;
 
     QFormLayoutPrivate();
     ~QFormLayoutPrivate() { }