Issue83 memory leak

See merge request !24

some pointers to keep those Arc struct alive, so Drop doesnt get called

impl Drop for VM

Ir validation

See merge request !23

# Conflicts:
#   src/ast/src/inst.rs
#   src/ast/src/ir.rs
#   src/ast/src/op.rs
#   src/ast/src/types.rs
#   src/vm/api/api_impl/muirbuilder.rs

This reverts commit a72984a8