Current jshell options are --

    -classpath <path> Specify where to find user class files
    -cp <path> Specify where to find user class files
    -startup <file> One run replacement for the start-up definitions
    -nostartup Do not run the start-up definitions
    -feedback <mode> Specify the initial feedback mode. The mode may be
                         predefined (silent, concise, normal, or verbose) or
                         previously user-defined
    -q Quiet feedback. Same as: -feedback concise
    -qq Really quiet feedback. Same as: -feedback silent
    -v Verbose feedback. Same as: -feedback verbose
    -J<flag> Pass <flag> directly to the runtime system.
                         Use one -J for each runtime flag or flag argument
    -R<flag> Pass <flag> to the remote runtime system.
                         Use one -R for each remote flag or flag argument
    -help Print this synopsis of standard options
    -version Version information
    -fullversion Full Version information

java current double-dash options are --

    -cp <class search path of directories and zip/jar files>
    -classpath <class search path of directories and zip/jar files>
    --class-path <class search path of directories and zip/jar files>
                  A : separated list of directories, JAR archives,
                  and ZIP archives to search for class files.
    -p <module path>
    --module-path <module path>...
                  A : separated list of directories, each directory
                  is a directory of modules.
    --upgrade-module-path <module path>...
                  A : separated list of directories, each directory
                  is a directory of modules that replace upgradeable
                  modules in the runtime image
    -m <module>[/<mainclass>]
    --module <modulename>[/<mainclass>]
                  the initial module to resolve, and the name of the main class
                  to execute if not specified by the module
    --add-modules <modulename>[,<modulename>...]
                  root modules to resolve in addition to the initial module.
                  <modulename> can also be ALL-DEFAULT, ALL-SYSTEM,
                  ALL-MODULE-PATH.
    --limit-modules <modulename>[,<modulename>...]
                  limit the universe of observable modules
    --list-modules [<modulename>[,<modulename>...]]
                  list the observable modules and exit
    --dry-run create VM but do not execute main method.
                  This --dry-run option may be useful for validating the
                  command-line options such as the module system configuration.

Of these, --class-path, --module-path, --add-modules, and maybe --upgrade-module-path seem appropriate for jshell.

Proposed for jshell --

    --class-path <path> Specify where to find user class files

    --module-path <module path>... directory of modules.
    -p <module path>

    --upgrade-module-path <module path>... directory of modules that replace upgradeable modules

    --add-modules <modulename>[,<modulename>...] root modules to resolve

    --startup <file> One run replacement for the start-up definitions

    --no-startup Do not run the start-up definitions
    -n

    --feedback <mode> Specify the initial feedback mode. The mode may be
                         predefined (silent, concise, normal, or verbose) or
                         previously user-defined

    -q Quiet feedback. Same as: --feedback concise

    -s Really quiet feedback. Same as: --feedback silent

    -v Verbose feedback. Same as: --feedback verbose

    -J<flag> Pass <flag> directly to the runtime system.

    -R<flag> Pass <flag> to the remote runtime system.

    --help Print this synopsis of standard options
    -h

    --version Version information

    --full-version Full Version information