This matches the output format used in HarfBuzz 2.7.4.

See:

* harfbuzz@5e89198
* harfbuzz#75 (comment)

HarfBuzz increased work limits for buffers in 2.7.3, causing results
for resource exhaustion tests (morx_34_001 and morx_36_001) to change.
We match these limits so that these tests pass.

See harfbuzz/harfbuzz@1c05f67.

RazrFalcon suggested leaving the test case format the same to
avoid overwriting all of the tests.

This applies the upstream 2.7.4 unviersal machine changes to the
Ragel files. Unfortunately, this means that we have to allocate
a vector in find_syllables, as we can’t do unholy things with
operator overloading unlike in C++.

This involves a `MachineCursor` type, which is equivalent to
HarfBuzz’s `machine_index`. Unfortunately, it is not possible to
overload the assignment operator in Rust, forcing us to manually
edit the generated source.