clif-util: Switch to using structopt for CLI arguments

Cargo.lock

@@ -548,7 +548,6 @@ dependencies = [
  "anyhow",
  "capstone",
  "cfg-if",
- "clap",
  "cranelift",
  "cranelift-codegen",
  "cranelift-entity",
@@ -570,6 +569,7 @@ dependencies = [
  "peepmatic-souper",
  "pretty_env_logger",
  "rayon",
+ "structopt",
  "target-lexicon",
  "term",
  "thiserror",
@@ -1972,9 +1972,9 @@ checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
 
 [[package]]
 name = "structopt"
-version = "0.3.15"
+version = "0.3.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "de2f5e239ee807089b62adce73e48c625e0ed80df02c7ab3f068f5db5281065c"
+checksum = "6cc388d94ffabf39b5ed5fadddc40147cb21e605f53db6f8f36a625d27489ac5"
 dependencies = [
  "clap",
  "lazy_static",
@@ -1983,9 +1983,9 @@ dependencies = [
 
 [[package]]
 name = "structopt-derive"
-version = "0.4.8"
+version = "0.4.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "510413f9de616762a4fbeab62509bf15c729603b72d7cd71280fbca431b1c118"
+checksum = "5e2513111825077552a6751dfad9e11ce0fba07d7276a3943a037d7e93e64c5f"
 dependencies = [
  "heck",
  "proc-macro-error",