The following fails to verify:

// ---
public class X {

static __ByValue class V {
        int x;
V() {
            int l = 0;
            l += x = 1234;
}
}

public static void main(String[] args) {
V v = new V();
System.out.println(v);
}
}


When run I get:
Exception in thread "main" java.lang.VerifyError: Bad type on operand stack
Exception Details:
  Location:
    X$V.$makeValue$()LX$V; @16: i2b
  Reason:
    Type 'X$V' (current frame, stack[1]) is not assignable to integer
  Current Frame:
    bci: @16
    flags: { }
    locals: { 'X$V', integer }
    stack: { integer, 'X$V' }
  Bytecode:
    0000000: cb00 064b 033c 1b2a 1104 d2cc 0007 594b
    0000010: 9160 3c2a b0

at X.main(X.java:12)