String.nqp

# Gets a string from a Unicode codepoint or other name
sub getstrfromname ( str $name ) {
    my int $cp := nqp::codepointfromname($name);
    return $cp < 0 ?? "" !! nqp::chr($cp);
}

The Java op version here should be (I'd add it to Ops.java below codepointfromname, line 4200 or so):

public static String (String name) {
    long cp = codepointfromname(name);
    /* I've inlined nqp::chr here, since it takes an additional ThreadContext argument
     * (so that it can throw an exception on cp < 0) which we don't need. */
    return cp < 0? "" : (new StringBuffer()).append(Character.toChars((int)ord)).toString();
}

You make it available to the compiler by adding a mapping to src/vm/jvm/QAST/Compiler.nqp (I'd add it after the mapping for codepointfromname, again):

QAST::OperationsJAST.map_classlib_core_op('getstrfromname', $TYPE_OPS, 'getstrfromname', [$RT_STR], $RT_STR);