Fix confusion in C++ file caused by comma in "= {1,2},".

Fix confusion in C++ file caused by comma in "= {1,2},".
cc-engine.el (c-beginning-of-statement-1): In checking for a statement
boundary marked by "}", check there's no "=" before the "{".
(c-guess-basic-syntax CASE 9B): Call c-beginning-of-statement with
non-nil `comma-delim' argument.
cc-fonts.el (c-font-lock-declarators): Parse an initializer expression
more accurately.