Add UTF_32 charsets to Charsets object as lazy initialized properties.

#KT-10379 Fixed

libraries/stdlib/src/kotlin/text/CharsetsJVM.kt

@@ -54,4 +54,41 @@ public object Charsets {
      */
     @JvmField
     public val ISO_8859_1: Charset = Charset.forName("ISO-8859-1")
+
+    /**
+     * 32-bit Unicode (or UCS) Transformation Format, byte order identified by an optional byte-order mark
+     */
+    public val UTF_32: Charset
+        @JvmName("UTF32")
+        get() = utf_32 ?: run {
+            val charset: Charset = Charset.forName("UTF-32")
+            utf_32 = charset
+            charset
+        }
+    private var utf_32: Charset? = null
+
+    /**
+     * 32-bit Unicode (or UCS) Transformation Format, little-endian byte order.
+     */
+    public val UTF_32LE: Charset
+        @JvmName("UTF32_LE")
+        get() = utf_32le ?: run {
+            val charset: Charset = Charset.forName("UTF-32LE")
+            utf_32le = charset
+            charset
+        }
+    private var utf_32le: Charset? = null
+
+    /**
+     * 32-bit Unicode (or UCS) Transformation Format, big-endian byte order.
+     */
+    public val UTF_32BE: Charset
+        @JvmName("UTF32_BE")
+        get() = utf_32be ?: run {
+            val charset: Charset = Charset.forName("UTF-32BE")
+            utf_32be = charset
+            charset
+        }
+    private var utf_32be: Charset? = null
+
 }

libraries/stdlib/test/text/StringJVMTest.kt

@@ -93,4 +93,10 @@ class StringJVMTest {
         assertEquals(listOf("Ast", "Beast", "asterisk"), list.sorted())
         assertEquals(listOf("Ast", "asterisk", "Beast"), list.sortedWith(String.CASE_INSENSITIVE_ORDER))
     }
+
+    @test fun charsets() {
+        assertEquals("UTF-32", Charsets.UTF_32.name())
+        assertEquals("UTF-32LE", Charsets.UTF_32LE.name())
+        assertEquals("UTF-32BE", Charsets.UTF_32BE.name())
+    }
 }