qmljs: update parser

Update the qtcreator qmljs parser to the
one of Qt 5.12. It supports EcmaScript 7.

Task-number: QTCREATORBUG-20341
Change-Id: I0d1cff71402ba17e22cde6b46c65614e162280de
Reviewed-by: Erik Verbruggen <erik.verbruggen@qt.io>

src/libs/qmljs/parser/qmljsmemorypool_p.h

@@ -56,13 +56,7 @@ class QML_PARSER_EXPORT MemoryPool : public QSharedData
     void operator =(const MemoryPool &other);
 
 public:
-    MemoryPool()
-        : _blocks(0),
-          _allocatedBlocks(0),
-          _blockCount(-1),
-          _ptr(0),
-          _end(0)
-    { }
+    MemoryPool() {}
 
     ~MemoryPool()
     {
@@ -74,6 +68,7 @@ public:
 
             free(_blocks);
         }
+        qDeleteAll(strings);
     }
 
     inline void *allocate(size_t size)
@@ -90,11 +85,16 @@ public:
     void reset()
     {
         _blockCount = -1;
-        _ptr = _end = 0;
+        _ptr = _end = nullptr;
     }
 
     template <typename Tp> Tp *New() { return new (this->allocate(sizeof(Tp))) Tp(); }
 
+    QStringRef newString(const QString &string) {
+        strings.append(new QString(string));
+        return QStringRef(strings.last());
+    }
+
 private:
     Q_NEVER_INLINE void *allocate_helper(size_t size)
     {
@@ -110,7 +110,7 @@ private:
             Q_CHECK_PTR(_blocks);
 
             for (int index = _blockCount; index < _allocatedBlocks; ++index)
-                _blocks[index] = 0;
+                _blocks[index] = nullptr;
         }
 
         char *&block = _blocks[_blockCount];
@@ -129,11 +129,12 @@ private:
     }
 
 private:
-    char **_blocks;
-    int _allocatedBlocks;
-    int _blockCount;
-    char *_ptr;
-    char *_end;
+    char **_blocks = nullptr;
+    int _allocatedBlocks = 0;
+    int _blockCount = -1;
+    char *_ptr = nullptr;
+    char *_end = nullptr;
+    QVector<QString*> strings;
 
     enum
     {
@@ -144,12 +145,10 @@ private:
 
 class QML_PARSER_EXPORT Managed
 {
-    Managed(const Managed &other);
-    void operator = (const Managed &other);
-
+    Q_DISABLE_COPY(Managed)
 public:
-    Managed() {}
-    ~Managed() {}
+    Managed() = default;
+    ~Managed() = default;
 
     void *operator new(size_t size, MemoryPool *pool) { return pool->allocate(size); }
     void operator delete(void *) {}