Adapt to latest CoreDSL 2 specification

[jopperm]

• Renamed args_disass tag to assembly.
• Always use Verilog-style literals in encoding.
• unsigned (w/o <width>) and int<width> are no longer valid.

These files are syntactically correct as of https://github.com/Minres/CoreDSL/commit/61737d3528188227cc43f041784ee2e5e17d9af5. We'll need to do a second pass over everything once the frontend fully checks the CoreDSL type rules.

[jopperm]

CC: @atomcrafty