QList/QVLA: default the parameter for indexOf/contains/remove/etc.

This allows to use list-initialization when calling these functions,
for instance list.removeAll({}).

Change-Id: I2828d900a44bd0bc5aea5fba4777304b09190bc9
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qlist.h

@@ -68,12 +68,12 @@ protected:
     const Self *self() const { return static_cast<const Self *>(this); }
 
 public:
-    template <typename AT>
+    template <typename AT = T>
     qsizetype indexOf(const AT &t, qsizetype from = 0) const noexcept;
-    template <typename AT>
+    template <typename AT = T>
     qsizetype lastIndexOf(const AT &t, qsizetype from = -1) const noexcept;
 
-    template <typename AT>
+    template <typename AT = T>
     bool contains(const AT &t) const noexcept
     {
         return self()->indexOf(t) != -1;
@@ -360,7 +360,7 @@ public:
 
     // QList compatibility
     void removeAt(qsizetype i) { remove(i); }
-    template <typename AT>
+    template <typename AT = T>
     qsizetype removeAll(const AT &t)
     {
         const const_iterator ce = this->cend(), cit = std::find(this->cbegin(), ce, t);
@@ -381,7 +381,7 @@ public:
         erase(it, e);
         return result;
     }
-    template <typename AT>
+    template <typename AT = T>
     bool removeOne(const AT &t)
     {
         const qsizetype i = indexOf(t);

src/corelib/tools/qvarlengtharray.h

@@ -190,11 +190,11 @@ public:
     inline qsizetype capacity() const { return a; }
     inline void reserve(qsizetype size);
 
-    template <typename AT>
+    template <typename AT = T>
     inline qsizetype indexOf(const AT &t, qsizetype from = 0) const;
-    template <typename AT>
+    template <typename AT = T>
     inline qsizetype lastIndexOf(const AT &t, qsizetype from = -1) const;
-    template <typename AT>
+    template <typename AT = T>
     inline bool contains(const AT &t) const;
 
     inline T &operator[](qsizetype idx)