vmctx leaks?

[YaronWittenstein]

It seems that vmctx is memory-leaked here:

1. Function::new_with_env
   

   wasmer/lib/api/src/externals/function.rs

   Line 137 in 518e0f3

   let vmctx = Box::into_raw(Box::new(dynamic_ctx)) as *mut VMContext;

2. Function::new_native_with_env

   wasmer/lib/api/src/externals/function.rs

   Line 230 in 518e0f3

   let vmctx = Box::into_raw(box_env) as *mut _ as *mut VMContext;