An implementation may extend program syntax and regular expression pattern
or flag syntax. To permit this, all operations (such as calling eval, using a
regular expression literal, or using the Function or RegExp constructor) that
are allowed to throw SyntaxError are permitted to exhibit
implementation-defined behaviour instead of throwing SyntaxError when they
encounter an implementation-defined extension to the program syntax or regular
expression pattern or flag syntax.
After consulting with the TC-39 committee, we've decided 'negative parser
tests' should be disabled unless ES5.1 explicitly calls out that
they should throw. E.g., literal octals in strings under Strict Mode would be
a valid negative test case we would not disable. Literal octals in strings outside of Strict Mode would *not* be a valid negative test case.
In the long term, the test harness and website will be adapted to allow opting-in WRT running these invalid albeit useful tests.
Disabling these is trivial; identifying them...not-so-much. Three days to implement this?
All tests identified by this Work Item and in test\config\excludelist.xml have been removed by Mark. Any other invalid tests will be removed on an as-needed basis.