8182854: jshell tool: rerun multiline snippet from history corrupts history (jdk part)
Summary: jdk sub-repo part of fix for parent issue 8182489, test in parent commit (langtools)
Reviewed-by: jlahoda

8178821: jshell tool: ctrl-down does nothing in current context
Summary: In MemoryHistory index() of an entry may go beyond size() (if some leading entries have been deleted) - using previous()/next() instead.
Reviewed-by: rfield

8178077: jshell tool: crash on ctrl-up or ctrl-down
Summary: When looking up a private method, using the ConsoleReader.class, instead of getClass(), which may return a subclass.
Reviewed-by: rfield

8166744: JShell: java.lang.IndexOutOfBoundsException for legal history access
Reviewed-by: rfield, jlahoda

8159031: jjs throws NoSuchFileException if ~/.jjs.history does not exist
Reviewed-by: sundar, mhaupt

8133549: Generalize jshell's EditingHistory
Summary: Adding a generic EditingHistory to jdk.internal.le, for use by both jjs and jshell
Reviewed-by: sundar