C++: Support noexcept operator

The code model failed to parse the noexcept operator which is often
used in noexcept specifiers, e.g.: "void f() noexcept(noexcept(g()));"
Consequently some c++11 headers such as unordered_map, array
and unordered_set could not be parsed and no code completition was
available. I have created the NoExceptOperatorExpressionAST class
which is created whenever a noexcept token is found in an
expression with operator precedence. The noExcept test case
in the cplusplus/cxx11 test now contains a function that
uses the noexcept operator.

Fixed noexcept operator parsing

Added the test requested by Sergey Shambir, which then revealed that
i had not implemeneted the noexpect operator parsing according to the
c++ specification.
As stated here http://cpp0x.centaur.ath.cx/expr.unary.noexcept.html
the noexcept operator is a unary-expression that contains an
expression (and not a constant-expression). This should now be fixed.

Change-Id: Id4a99a43b660bd83e7680274491d99a698b57094
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

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

@@ -837,6 +837,13 @@ public:
         return ast;
     }
 
+    NoExceptOperatorExpressionAST *NoExceptOperatorExpression(ExpressionAST *expression = 0)
+    {
+        NoExceptOperatorExpressionAST *ast = new (&pool) NoExceptOperatorExpressionAST;
+        ast->expression = expression;
+        return ast;
+    }
+
     TranslationUnitAST *TranslationUnit(DeclarationListAST *declaration_list = 0)
     {
         TranslationUnitAST *ast = new (&pool) TranslationUnitAST;