Instead of always reporting a colno and lineno of zero try and use the
values from the Error object that may be provided, falling back to the
source location of the invocation if not provided. We can definitely
improve the reporting even more, but this is a start!
Also update this function to latest spec while we're in the area.
The 'reason' was getting initialized to 'empty' state when not
provided through the constructor, which results in a crash when
accessed through throw_dom_exception_if_needed in the generated
IDL getter.
This fixes structured serialization of DataView. It was expected
to be uniform with TypedArray, which returns u32 for byte_offset().
This was covered by a number of WPT infrastructure tests, which this
commit also imports.