Address CR feedback

Author: ahejlsberg

tests/baselines/reference/indexSignatureAndMappedType.errors.txt

@@ -15,7 +15,7 @@ tests/cases/compiler/indexSignatureAndMappedType.ts(16,5): error TS2322: Type '{
 !!! error TS2322: Type '{ [key: string]: T; }' is not assignable to type 'Record<K, T>'.
     }
 
-    function f2<T, K extends string>(x: { [key: string]: T }, y: Record<string, T>) {
+    function f2<T>(x: { [key: string]: T }, y: Record<string, T>) {
         x = y;
         y = x;
     }

tests/baselines/reference/indexSignatureAndMappedType.js

@@ -7,7 +7,7 @@ function f1<T, K extends string>(x: { [key: string]: T }, y: Record<K, T>) {
     y = x;  // Error
 }
 
-function f2<T, K extends string>(x: { [key: string]: T }, y: Record<string, T>) {
+function f2<T>(x: { [key: string]: T }, y: Record<string, T>) {
     x = y;
     y = x;
 }
@@ -55,7 +55,7 @@ function f3(x, y) {
 declare function f1<T, K extends string>(x: {
     [key: string]: T;
 }, y: Record<K, T>): void;
-declare function f2<T, K extends string>(x: {
+declare function f2<T>(x: {
     [key: string]: T;
 }, y: Record<string, T>): void;
 declare function f3<T, U, K extends string>(x: {

tests/cases/compiler/indexSignatureAndMappedType.ts

@@ -9,7 +9,7 @@ function f1<T, K extends string>(x: { [key: string]: T }, y: Record<K, T>) {
     y = x;  // Error
 }
 
-function f2<T, K extends string>(x: { [key: string]: T }, y: Record<string, T>) {
+function f2<T>(x: { [key: string]: T }, y: Record<string, T>) {
     x = y;
     y = x;
 }