IR builder fails on zsuper with kwargs from within block

[headius]

Here's the code and output. It's not too complicated, but it crashes the builder. Getting late here for me so I can't fix it right now.

$ ruby -e "class X1; def foo(a: 1, b:); p a, b; end; end; class X2 < X1; def foo(a:, b:); 1.times { super }; end; end; X2.new.foo(a:3, b:4)"
IRBuilder.java:3513:in `adjustVariableDepth': java.lang.ClassCastException: org.jruby.ir.operands.Hash cannot be cast to org.jruby.ir.operands.DepthCloneable
    from IRBuilder.java:81:in `access$000'
    from IRBuilder.java:3475:in `run'
    from IRBuilder.java:939:in `receiveBreakException'
    from IRBuilder.java:3488:in `buildZSuperIfNest'
    from IRBuilder.java:3501:in `buildZSuper'
    from IRBuilder.java:456:in `buildOperand'
    from IRBuilder.java:500:in `build'
    from IRBuilder.java:2700:in `buildNewline'
    from IRBuilder.java:418:in `buildOperand'
    from IRBuilder.java:500:in `build'
    from IRBuilder.java:2534:in `buildIter'
    from IRBuilder.java:407:in `buildOperand'
    from IRBuilder.java:500:in `build'
    from IRBuilder.java:2244:in `setupCallClosure'
    from IRBuilder.java:989:in `buildCall'
    from IRBuilder.java:371:in `buildOperand'
    from IRBuilder.java:500:in `build'
    from IRBuilder.java:2700:in `buildNewline'
    from IRBuilder.java:418:in `buildOperand'
    from IRBuilder.java:500:in `build'
    from IRBuilder.java:1685:in `defineMethodInner'
    from IRBuilder.java:1702:in `defineNewMethod'
    from IRBuilder.java:1706:in `buildDefn'
    from IRBuilder.java:384:in `buildOperand'
    from IRBuilder.java:500:in `build'
    from IRBuilder.java:2700:in `buildNewline'
    from IRBuilder.java:418:in `buildOperand'
    from IRBuilder.java:500:in `build'
    from IRBuilder.java:3536:in `buildModuleOrClassBody'
    from IRBuilder.java:1115:in `buildClass'
    from IRBuilder.java:373:in `buildOperand'
    from IRBuilder.java:500:in `build'
    from IRBuilder.java:2700:in `buildNewline'
    from IRBuilder.java:418:in `buildOperand'
    from IRBuilder.java:500:in `build'
    from IRBuilder.java:865:in `buildBlock'
    from IRBuilder.java:369:in `buildOperand'
    from IRBuilder.java:500:in `build'
    from IRBuilder.java:3259:in `buildRoot'
    from IRTranslator.java:26:in `execute'
    from Ruby.java:850:in `runInterpreter'
    from Ruby.java:858:in `runInterpreter'
    from Ruby.java:754:in `runNormally'
    from Ruby.java:559:in `runFromMain'
    from Main.java:405:in `doRunFromMain'
    from Main.java:300:in `internalRun'
    from Main.java:227:in `run'
    from Main.java:199:in `main'