fix(Generic Constraints d.ts): add to d.ts generic type parameters constraints.

js/js.translator/testData/typescript-export/declarations/declarations.d.ts

@@ -16,6 +16,8 @@ declare namespace JS_TESTS {
         function defaultParameters(x: number, y: string): string;
         function generic1<T>(x: T): T;
         function generic2<T>(x: Nullable<T>): boolean;
+        function genericWithConstraint<T extends string>(x: T): T;
+        function genericWithMultipleConstraints<T extends foo.TestInterface & Error>(x: T): T;
         function generic3<A, B, C, D, E>(a: A, b: B, c: C, d: D): Nullable<E>;
         function inlineFun(x: number, callback: (p0: number) => void): void;
         const _const_val: number;

js/js.translator/testData/typescript-export/declarations/declarations.kt

@@ -44,6 +44,15 @@ fun <T> generic1(x: T): T = x
 @JsExport
 fun <T> generic2(x: T?): Boolean = (x == null)
 
+@JsExport
+fun <T: String> genericWithConstraint(x: T): T = x
+
+@JsExport
+fun <T> genericWithMultipleConstraints(x: T): T
+        where T : Comparable<T>,
+              T : TestInterface,
+              T : Throwable = x
+
 @JsExport
 fun <A, B, C, D, E> generic3(a: A, b: B, c: C, d: D): E? = null