Now that we are building with C++11 features enabled, replace use
of NULL with nullptr.
The benefit of using nullptr is that it can never be confused for
an integral type because it does not support implicit conversions
to integral types except boolean - unlike NULL, which is defined
as a literal `0`.
Previously v8's WriteUtf8 function would produce invalid utf-8 output
when encountering unmatched surrogate code units [1]. The new
REPLACE_INVALID_UTF8 option fixes that by replacing invalid code points
with the unicode replacement character.
[1]: JS Strings are defined as arrays of 16 bit unsigned integers. There
is no unicode enforcement, so one can easily end up with invalid unicode
code unit sequences inside a string.
Performs a quick, non-exhaustive check on the input string to see if
it's compatible with the specified string encoding.
Curently it only checks that hex strings have a length that is a
multiple of two.
It imports the definition into every source file that includes
string_bytes.h, as evidenced by the build suddenly breaking left
and right because of missing Handle/Local/String/Value imports.