Update to clap 3.* (#4082)

* Update to clap 3.0

This commit migrates all CLI commands internally used in this project
from structopt/clap2 to clap 3. The intent here is to ensure that we're
using maintained versions of the dependencies as structopt and clap 2
are less maintained nowadays. Most transitions were pretty
straightforward and mostly dealing with structopt/clap3 differences.

* Fix a number of `cargo deny` errors

This commit fixes a few errors around duplicate dependencies which
arose from the prior update to clap3. This also uses a new feature in
`deny.toml`, `skip-tree`, which allows having a bit more targeted
ignores for skips of duplicate version checks. This showed a few more
locations in Wasmtime itself where we could update some dependencies.

cranelift/src/compile.rs

@@ -3,6 +3,7 @@
 use crate::disasm::print_all;
 use crate::utils::{parse_sets_and_triple, read_to_string};
 use anyhow::{Context as _, Result};
+use clap::Parser;
 use cranelift_codegen::print_errors::pretty_error;
 use cranelift_codegen::settings::FlagsOrIsa;
 use cranelift_codegen::timing;
@@ -10,37 +11,35 @@ use cranelift_codegen::Context;
 use cranelift_reader::{parse_test, ParseOptions};
 use std::path::Path;
 use std::path::PathBuf;
-use structopt::StructOpt;
 
 /// Compiles Cranelift IR into target language
-#[derive(StructOpt)]
+#[derive(Parser)]
 pub struct Options {
     /// Print the resulting Cranelift IR
-    #[structopt(short("p"))]
+    #[clap(short)]
     print: bool,
 
     /// Print pass timing report
-    #[structopt(short("T"))]
+    #[clap(short = 'T')]
     report_times: bool,
 
     /// Print machine code disassembly
-    #[structopt(short("D"), long("disasm"))]
+    #[clap(short = 'D', long)]
     disasm: bool,
 
     /// Configure Cranelift settings
-    #[structopt(long("set"))]
+    #[clap(long = "set")]
     settings: Vec<String>,
 
     /// Specify the Cranelift target
-    #[structopt(long("target"))]
+    #[clap(long = "target")]
     target: String,
 
     /// Specify an input file to be used. Use '-' for stdin.
-    #[structopt(parse(from_os_str))]
     files: Vec<PathBuf>,
 
     /// Enable debug output on stderr/stdout
-    #[structopt(short = "d")]
+    #[clap(short)]
     debug: bool,
 }