qualify RUBY_ENGINE_OPAL constant
qualify RUBY_ENGINE_OPAL constant

mjang/mj-asciidoc,benignbala/asciidoctor,gjtorikian/asciidoctor,asciidocfx/asciidoctor,neontapir/asciidoctor,cuit-zhaxin/asciidoctor,cuit-zhaxin/asciidoctor,asciidocfx/asciidoctor,anthonny/asciidoctor,benignbala/asciidoctor,mjang/mj-asciidoc,glamouracademy/asciidoctor,pepijnve/asciidoctor,neontapir/asciidoctor,anthonny/asciidoctor,pepijnve/asciidoctor,gjtorikian/asciidoctor,yukisan/asciidoctor,yukisan/asciidoctor,glamouracademy/asciidoctor