OpcodeCall.StaticExecute throws nullptr when a delegate without a closure is executed

[BAM5]

This is happens when using OpcodePushDelegate or OpcodePushDelegateRelocateLater with the WithClosure field set to false.

A simple nullptr check ahead of this line will fix this.

KOS/src/kOS.Safe/Compilation/Opcode.cs

Line 1799 in 9e7678c

for (int i = userDelegate.Closure.Count - 1 ; i >= 0 ; --i)

(.Closure is null)