chore: remove comments about missing functionality now implemented elsewhere

Author: zwarich

src/Lean/Compiler/LCNF/ToDecl.lean

@@ -131,11 +131,6 @@ def toDecl (declName : Name) : CompilerM Decl := do
       let value ← inlineMatchers value
       /- Recall that `inlineMatchers` may have exposed `ite`s and `dite`s which are tagged as `[macro_inline]`. -/
       let value ← macroInline value
-      /-
-      Remark: we have disabled the following transformatbion, we will perform it at phase 2, after code specialization.
-      It prevents many optimizations (e.g., "cases-of-ctor").
-      -/
-      -- let value ← applyCasesOnImplementedBy value
       return (type, value)
     let code ← toLCNF value
     let decl ← if let .fun decl (.return _) := code then

src/Lean/Compiler/LCNF/ToMono.lean

@@ -278,7 +278,6 @@ partial def Code.toMono (code : Code) : ToMonoM Code := do
     else if let some info ← hasTrivialStructure? c.typeName then
       trivialStructToMono info c
     else
-      -- TODO: `casesOn` `[implemented_by]` support
       let type ← toMonoType c.resultType
       let alts ← c.alts.mapM fun alt =>
         match alt with