C++11: Fix parsing of expressions like vector<int>{1}.

The parser considers '{' an operator and thus thought
"template-id {" couldn't possibly be valid. This patch adds
'{' as an exception to the rule.

Change-Id: I40730fcdc5cade48566b4c8b6fde390f455bbdba
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>