v0.8.0

Tier 4: the loop closes

The front end, written in the language the self-hosted compiler compiles.
glyphc.gsl2 is the whole of tier 1 - preprocessor, transducer, parser,
analyser, pass manager, assembler - and the tier 2 lowering after it,
written a second time in GSL-2. The seed turns the crank once, on the
GSL-2 compiler alone, and nothing downstream of it runs an interpreter.

python3 -> gslc -> gslc -> glyphc -> glyph

The claim is byte equality, not agreement: for any program both accept,
the front end and layer 16 emit the same file.

LOC: 10766