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>

tests/auto/cplusplus/cxx11/data/braceInitializers.3.cpp

@@ -1,6 +1,7 @@
 auto x = int{};
 auto y = Foo{};
 auto z = typename Foo<T>{};
+auto a = Foo<T>{};
 
 auto d = new C(1, abc...);
 auto e = new C{1, 2, 3};