LoadError with compiled multi-byte constant

multibyteconst.rb
```
# coding: utf-8

# 'α'.bytes => [206, 177]
p CONST_α = 1
```
run with jruby 9.1.9.0
```
$ jruby multibyteconst.rb
1
```
compile and run with jruby 9.1.9.0
```
$ jrubyc multibyteconst.rb
$ jruby multibyteconst.class
LoadError: multibyteconst.class is not compiled Ruby; use java_import to load normal classes
```
