8337245: Fix wrong comment of StringConcatHelper

Reviewed-by: phh, redestad

Author: wenshao

src/java.base/share/classes/java/lang/StringConcatHelper.java

@@ -185,7 +185,7 @@ static long prepend(long indexCoder, byte[] buf, boolean value, String prefix) {
      * @param indexCoder final char index in the buffer, along with coder packed
      *                   into higher bits.
      * @param buf        buffer to append to
-     * @param value      boolean value to encode
+     * @param value      char value to encode
      * @param prefix     a constant to prepend before value
      * @return           updated index (coder value retained)
      */
@@ -211,7 +211,7 @@ static long prepend(long indexCoder, byte[] buf, char value, String prefix) {
      * @param indexCoder final char index in the buffer, along with coder packed
      *                   into higher bits.
      * @param buf        buffer to append to
-     * @param value      boolean value to encode
+     * @param value      int value to encode
      * @param prefix     a constant to prepend before value
      * @return           updated index (coder value retained)
      */
@@ -237,7 +237,7 @@ static long prepend(long indexCoder, byte[] buf, int value, String prefix) {
      * @param indexCoder final char index in the buffer, along with coder packed
      *                   into higher bits.
      * @param buf        buffer to append to
-     * @param value      boolean value to encode
+     * @param value      long value to encode
      * @param prefix     a constant to prepend before value
      * @return           updated index (coder value retained)
      */