hg: jdk/sandbox: 8183554: Add constructors with Charset parameter for FileReader and FileWriter

[chris.hegarty at oracle.com]

Changeset: 422615764e12
Author:    joehw
Date:      2018-03-15 14:54 -0700
URL:       http://hg.openjdk.java.net/jdk/sandbox/rev/422615764e12

8183554: Add constructors with Charset parameter for FileReader and FileWriter
Reviewed-by: alanb, rriggs, smarks

! src/java.base/share/classes/java/io/FileReader.java
! src/java.base/share/classes/java/io/FileWriter.java
+ test/jdk/java/io/FileReader/ConstructorTest.java
+ test/jdk/java/io/FileWriter/ConstructorTest.java