Add support of syntax error checking

[sand1k]

• implement setjmp / longjmp
• add checks into parsing of expression
  • 11.1.5
  • 11.3.1
  • 11.3.2
  • 11.4.1
  • 11.4.4
  • 11.4.5
  • 11.13.1
  • 11.13.2
  • 12.2.1
  • 12.10.1
  • 12.14.1
  • 13.1

[galpeter]

One test case to consider which was raised during the review of the eval implementation (#174) is the following:

var r = function() { return eval('return 1;'); };
try {
    r();
    print("fail");
    assert(false);
} catch (e) {
    print(e);
    assert(e instanceof SyntaxError);
}

It prints out the fail message, but a SyntaxError should be thrown. Other engines reports the error with the "return not in function" message.

[ruben-ayrapetyan]

@galpeter, thank you for the case.

[egavrin]

@sand1k please recheck this issue after unicode implementation