Switch to fully dynamically dispatched salsa

[matklad]

This improves compile times quite a bit

bors r+
🤖

[bors]

Build succeeded:

• TypeScript (windows-latest)
• Rust (ubuntu-latest)
• Rust (windows-latest)
• Rust (macos-latest)
• TypeScript (ubuntu-latest)
• TypeScript (macos-latest)

[kjeremy]

Perf/memory impact?

[lnicola]

Not much, some slight memory usage decrease:

Database loaded 282.166469ms
Crates in this dir: 37
Total modules found: 489
Total declarations: 9571
Total functions: 7451
Item Collection: 17.752670785s, 0b allocated 0b resident
Total expressions: 191940                                                                                                                          
Expressions of unknown type: 1564 (0%)
Expressions of partially unknown type: 943 (0%)
Type mismatches: 455
Inference: 29.180093714s, 0b allocated 0b resident
Total: 46.932773185s, 0b allocated 0b resident
47.76user 0.71system 0:48.57elapsed 99%CPU (0avgtext+0avgdata 1452196maxresident)k
0inputs+0outputs (0major+381613minor)pagefaults 0swaps

Database loaded 274.277544ms
Crates in this dir: 37
Total modules found: 489
Total declarations: 9571
Total functions: 7451
Item Collection: 17.483419404s, 0b allocated 0b resident
Total expressions: 191940                                                                                                                        
Expressions of unknown type: 1576 (0%)
Expressions of partially unknown type: 955 (0%)
Type mismatches: 455
Inference: 28.555933121s, 0b allocated 0b resident
Total: 46.039360356s, 0b allocated 0b resident
46.81user 0.72system 0:47.65elapsed 99%CPU (0avgtext+0avgdata 1398384maxresident)k
0inputs+0outputs (0major+368339minor)pagefaults 0swaps