support.pyrepl: do not crash if _ is not defined. This happens e.g. if the first entered statement is `import foo`.

pyrepl→support.pyrepl

internal_test: remove. Outdated, bitrotted, not very useful, and confusing since it shows up in --help.

arch.lpc: new definitions.

gateware.fx2: implement reset for async FIFOs.

cli: build: fix a confusing message.

revC: fix some more diffpair issues

revC: fix up diffpairs Moved skew matching meanders to the FPGA side, length matched again. Kicad is being stupid about length matching so I could only get them to within +/- 0.5mm, but that should be plenty.

revC: update wave soldering keepouts

revC: add ATECC508A