Utils: Remove odd QTreeView declaration from environmentfwd.h

... and use one when it is really needed.

Change-Id: I583fb775e5d625833816ac380ea74bf24b67d8e7
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/libs/utils/environmentfwd.h

@@ -5,11 +5,8 @@
 
 #include <QList>
 
-QT_BEGIN_NAMESPACE
-class QTreeView;
-QT_END_NAMESPACE
-
 namespace Utils {
+
 class NameValueDictionary;
 class NameValueItem;
 using NameValueItems = QList<NameValueItem>;
@@ -24,4 +21,5 @@ using PreprocessorMacroItems = NameValueItems;
 
 class NameValueModel;
 class EnvironmentModel;
+
 } // namespace Utils

src/libs/utils/namevaluevalidator.h

@@ -5,14 +5,13 @@
 
 #include "utils_global.h"
 
-#include "environmentfwd.h"
-
 #include <QPersistentModelIndex>
 #include <QTimer>
 #include <QValidator>
 
 QT_BEGIN_NAMESPACE
 class QModelIndex;
+class QTreeView;
 QT_END_NAMESPACE
 
 namespace Utils {

src/plugins/clangtools/clangselectablefilesdialog.h

@@ -9,6 +9,7 @@
 
 QT_BEGIN_NAMESPACE
 class QComboBox;
+class QTreeView;
 QT_END_NAMESPACE
 
 namespace ClangTools {

src/plugins/cppeditor/cppcodemodelinspectordialog.h

@@ -17,6 +17,7 @@ class QModelIndex;
 class QPlainTextEdit;
 class QSortFilterProxyModel;
 class QTabWidget;
+class QTreeView;
 QT_END_NAMESPACE
 
 namespace CppEditor::Internal {