C++ Mode: Prevent End of statement being found after {} in "count << vec{} <<"

C++ Mode: Prevent End of statement being found after {} in "count << vec{} <<"

* lisp/progmodes/cc-engine.el (c-beginning-of-statement-1): Check for
operators which cannot start a statement, which may follow a closing brace.
Don't recognise an end of statement in such a case.

* lisp/progmodes/cc-langs.el (c-operator-re, c-bin-tern-operators)
(c-unary-operators, c-non-after-{}-operators, c-non-after-{}-ops-re): New lang
consts and vars.