[stdlib-js-ir] Add equals, hashCode, toString to some builtins

Namely:
* Throwable;
* primitive numbers except Long (which implemented in Kotlin).

libraries/stdlib/js-ir/builtins/Primitives.kt

@@ -218,6 +218,10 @@ public class Byte private constructor() : Number(), Comparable<Byte> {
      * The resulting `Double` value represents the same numerical value as this `Byte`.
      */
     public override fun toDouble(): Double
+
+    public override fun equals(other: Any?): Boolean
+    public override fun hashCode(): Int
+    public override fun toString(): String
 }
 
 /**
@@ -428,6 +432,10 @@ public class Short private constructor() : Number(), Comparable<Short> {
      * The resulting `Double` value represents the same numerical value as this `Short`.
      */
     public override fun toDouble(): Double
+
+    public override fun equals(other: Any?): Boolean
+    public override fun hashCode(): Int
+    public override fun toString(): String
 }
 
 /**
@@ -657,6 +665,10 @@ public class Int private constructor() : Number(), Comparable<Int> {
      * The resulting `Double` value represents the same numerical value as this `Int`.
      */
     public override fun toDouble(): Double
+
+    public override fun equals(other: Any?): Boolean
+    public override fun hashCode(): Int
+    public override fun toString(): String
 }
 
 /**
@@ -863,6 +875,10 @@ public class Float private constructor() : Number(), Comparable<Float> {
      * The resulting `Double` value represents the same numerical value as this `Float`.
      */
     public override fun toDouble(): Double
+
+    public override fun equals(other: Any?): Boolean
+    public override fun hashCode(): Int
+    public override fun toString(): String
 }
 
 /**
@@ -1071,5 +1087,9 @@ public class Double private constructor() : Number(), Comparable<Double> {
     public override fun toFloat(): Float
     /** Returns this value. */
     public override fun toDouble(): Double
+
+    public override fun equals(other: Any?): Boolean
+    public override fun hashCode(): Int
+    public override fun toString(): String
 }