C: Parser: Support parsing of c99 designated initializers

In case:

    int a[6] = { [4] = 29, [2] = 15 };
    struct point { int x, y; };
    struct point p = { .y = 3, .x = 2 };

Grammar change when c99 language feature is enabled:
old grammar:

    braced-init-list :: '{' initializer-list '}'

new grammar:

    braced-init-list :: '{' designated-initializer-list '}'
    designated-initializer-list :: designated-initializer (',' designated-initializer )*
    designated-initializer :: designator* initializer-clause
    designator :: '.' identifier
                | '[' constant-expression ']'

Task-number: QTCREATORBUG-1902
Change-Id: Ib99d6f553f8d0f50ba3eff86f3a2e86d73372426
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>

src/libs/3rdparty/cplusplus/ASTPatternBuilder.h

@@ -1147,6 +1147,20 @@ public:
         return __ast;
     }
 
+    DesignatorAST *Designator()
+    {
+        DesignatorAST *__ast = new (&pool) DesignatorAST;
+        return __ast;
+    }
+
+    DesignatedInitializerAST *DesignatedInitializer(DesignatorListAST *designator_list = 0, ExpressionAST *initializer = 0)
+    {
+        DesignatedInitializerAST *__ast = new (&pool) DesignatedInitializerAST;
+        __ast->designator_list = designator_list;
+        __ast->initializer = initializer;
+        return __ast;
+    }
+
     AttributeListAST *AttributeList(AttributeAST *value, AttributeListAST *next = 0)
     {
         AttributeListAST *__list = new (&pool) AttributeListAST;
@@ -1195,6 +1209,14 @@ public:
         return __list;
     }
 
+    DesignatorListAST *DesignatorList(DesignatorAST *value, DesignatorListAST *next = 0)
+    {
+        DesignatorListAST *__list = new (&pool) DesignatorListAST;
+        __list->next = next;
+        __list->value = value;
+        return __list;
+    }
+
     EnumeratorListAST *EnumeratorList(EnumeratorAST *value, EnumeratorListAST *next = 0)
     {
         EnumeratorListAST *__list = new (&pool) EnumeratorListAST;