fix: Type param hover shows correct sized bounds.

[iDawer]

Closes #9949

This adds implicit : Sized bound to type parameters at lowering step.

Hovering on type parameter does not show it's : Sized bound be it set explicitly or implicitly. This is because it doesn't track that the bound was set implicitly.

Perf

./target/rust-analyzer-baseline-3dae94bf -q analysis-stats --memory-usage .
Database loaded:     4.51s, 311minstr, 110mb (metadata 1.08s, 22minstr, 743kb; build 3.20s, 8730kinstr, -237kb)
  crates: 38, mods: 770, decls: 17173, fns: 12835
Item Collection:     29.63s, 85ginstr, 372mb
  exprs: 353460, ??ty: 364 (0%), ?ty: 232 (0%), !ty: 144
Inference:           118.25s, 284ginstr, 601mb
Total:               147.88s, 370ginstr, 973mb

./target/rust-analyzer-hover-ty-param-dfb15292 -q analysis-stats --memory-usage .
Database loaded:     4.53s, 311minstr, 110mb (metadata 1.10s, 22minstr, 743kb; build 3.20s, 8672kinstr, -189kb)
  crates: 38, mods: 770, decls: 17173, fns: 12835
Item Collection:     29.59s, 85ginstr, 372mb
  exprs: 353460, ??ty: 364 (0%), ?ty: 232 (0%), !ty: 144
Inference:           121.69s, 296ginstr, 601mb
Total:               151.28s, 382ginstr, 974mb

[flodiebold]

bors r+

[bors]

Build succeeded:

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