[Patterns] Missing boxing conversion after instanceof leads to verify error

[srikanth-sankaran]

This is a regression from #2011

We are failing to emit a boxing operation which leads to verify error in this code:

public class X {
	
	public static void foo(Boolean b) {
		
	}
	
	public static void main(String [] args) {
		Object o = new Object();
		foo(o instanceof String);
	        System.out.println("Done!");
	}
}

This code when compiled on master fails with:

Error: Unable to initialize main class X
Caused by: java.lang.VerifyError: Bad type on operand stack
Exception Details:
  Location:
    X.main([Ljava/lang/String;)V @12: invokestatic
  Reason:
    Type integer (current frame, stack[0]) is not assignable to 'java/lang/Boolean'
  Current Frame:
    bci: @12
    flags: { }
    locals: { '[Ljava/lang/String;', 'java/lang/Object' }
    stack: { integer }
  Bytecode:
    0000000: bb00 0359 b700 084c 2bc1 0014 b800 16b2
    0000010: 0018 121e b600 20b1                    

On 4.31 RC2 it prints Done! as expected.

This is also the reason behind the remaining two comparator errors in eclipse-platform/eclipse.platform.releng.aggregator#1875 (comment)