OpenJDK 11: Merging in java.io.FileReader and FileWriter

This is part of merging upstream changes from OpenJDK 11.28. This CL
merges java.io.FileReader and FileWriter.

There are 2 new constructors added for java.io.FileReader:
    FileReader(String, Charset) throws IOException;
    FileReader(File, Charset) throws IOException;

And 4 added for FileWriter:
    FileWriter(String, Charset) throws IOException;
    FileWriter(String, Charset, boolean) throws IOException;
    FileWriter(File, Charset) throws IOException;
    FileWriter(File, Charset, boolean) throws IOException;

Tests were added for all of the new constructors

Test: m droid
Test: atest CtsLibcoreTestCases:libcore.java.io.FileReader.ConstructorTest
Test: atest CtsLibcoreTestCases:libcore.java.io.FileWriter.ConstructorTest
Change-Id: I7fdeec6d99a1c9315791427b4ad6a1614d8b4c5f
5 files changed