8341228ffa
Properly skip parentheses around an rvalue, and then properly recognize
the surrounded value. This allows to properly recognize e.g. rvalue
`({...})` as an object, or `(function(){})` as a function. As the
implementation is tolerant regarding garbage after the statement,
function expressions called straight away (`(function(){})()`) are
implicitly supported.
This however removes support for the following invalid JavaScript
syntax that was previously supported as a function/method declaration:
var func = () {}
This syntax is not present in the ECMA standard nor is supported by
popular JavaScript engines.
See:
* http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-262.pdf
section 13, "Function Definition"
* http://ecma262-5.com/ELS5_HTML.htm#Section_13
* https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions_and_function_scope#Defining_functions