feat(dso): implement unused DSO cleaner

This is the first implementation of a recursive
DSO cleaner which is reasonably fast.

The implementation is still (unit-) untested.

Of course, modules to be dlopen'ed will always
escape such a tool, which will need to
support another cleaner plugin with a
whitelist.

Cargo.lock

@@ -298,6 +298,15 @@ version = "2.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
 
+[[package]]
+name = "memmap2"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd3f7eed9d3848f8b98834af67102b720745c4ec028fcd0aa0239277e7de374f"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "miniz_oxide"
 version = "0.8.3"
@@ -539,6 +548,7 @@ dependencies = [
  "env_logger",
  "goblin",
  "log",
+ "memmap2",
  "nix",
  "petgraph",
  "tokio",