If a malicious actor holds a reference to the argument array passed to MethodTypeDesc.of factory, it can mutate a supposingly immutable MethodTypeDesc and create an illegal MethodTypeDesc.

    jshell> import java.lang.constant.*;
    
    jshell> import java.lang.invoke.*;
    
    jshell> import static java.lang.constant.ConstantDescs.*;
    
    jshell> ClassDesc[] args = { CD_int, CD_Long};
    args ==> ClassDesc[2] { PrimitiveClassDesc[int], ClassDesc[Long] }
    
    jshell> var mtd = MethodTypeDesc.of(CD_void, args);
    mtd ==> MethodTypeDesc[(int,Long)void]
    
    jshell> mtd
    mtd ==> MethodTypeDesc[(int,Long)void]
    
    jshell> args[1] = CD_void
    $7 ==> PrimitiveClassDesc[void]
    
    jshell> mtd
    mtd ==> MethodTypeDesc[(int,void)void]

I recommend changing MethodTypeDescImpl to be list-backed than array-backed to reduce allocations on `parameterList` calls too.