Simplified JS prototype class inference

src/compiler/types.ts

@@ -2237,7 +2237,6 @@ namespace ts {
         declaration: SignatureDeclaration;  // Originating declaration
         typeParameters: TypeParameter[];    // Type parameters (undefined if non-generic)
         parameters: Symbol[];               // Parameters
-        kind: SignatureKind;                // Call or Construct
         typePredicate?: TypePredicate;      // Type predicate
         /* @internal */
         resolvedReturnType: Type;           // Resolved return type