QAbstractItemModel::match: code tidies

Remove a magic number from the code, by adding it (as a private value)
to the right enumeration. Use toInt() to convert to integer.

Change-Id: Id1b00dde900619684b5a3df247d46938439150ca
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/global/qnamespace.h

@@ -1547,6 +1547,7 @@ namespace Qt {
         MatchRegularExpression = 4,
         MatchWildcard = 5,
         MatchFixedString = 8,
+        MatchTypeMask = 0x0F,
         MatchCaseSensitive = 16,
         MatchWrap = 32,
         MatchRecursive = 64

src/corelib/global/qnamespace.qdoc

@@ -2838,6 +2838,7 @@
            the search reaches the last item in the model, it begins again at
            the first item and continues until all items have been examined.
     \value MatchRecursive          Searches the entire hierarchy.
+    \omitvalue MatchTypeMask
 
     \sa QString::compare(), QRegularExpression
 */

src/corelib/itemmodels/qabstractitemmodel.cpp

@@ -2533,7 +2533,7 @@ QModelIndexList QAbstractItemModel::match(const QModelIndex &start, int role,
                                           Qt::MatchFlags flags) const
 {
     QModelIndexList result;
-    uint matchType = flags & 0x0F;
+    uint matchType = (flags & Qt::MatchTypeMask).toInt();
     Qt::CaseSensitivity cs = flags & Qt::MatchCaseSensitive ? Qt::CaseSensitive : Qt::CaseInsensitive;
     bool recurse = flags & Qt::MatchRecursive;
     bool wrap = flags & Qt::MatchWrap;