Readopt older candidateType check, even though it shouldnt really matter

Author: weswigham

src/compiler/checker.ts

@@ -20568,7 +20568,7 @@ namespace ts {
                     // this a literal context for literals of that primitive type. For example, given a
                     // type parameter 'T extends string', infer string literal types for T.
                     const constraint = getBaseConstraintOfType(contextualType) || emptyObjectType;
-                    return constraint === keyofConstraintType ||
+                    return constraint === keyofConstraintType && maybeTypeOfKind(candidateType, TypeFlags.StringLiteral | TypeFlags.NumberLiteral | TypeFlags.UniqueESSymbol) ||
                         constraint.flags & TypeFlags.String && maybeTypeOfKind(candidateType, TypeFlags.StringLiteral) ||
                         constraint.flags & TypeFlags.Number && maybeTypeOfKind(candidateType, TypeFlags.NumberLiteral) ||
                         constraint.flags & TypeFlags.Boolean && maybeTypeOfKind(candidateType, TypeFlags.BooleanLiteral) ||