Add "developer" feature and put "debug" command behind it.

Add a "developer" feature that enables the debug command. Prior to this the
command was always available but just hidden. This makes it a compile-time
feature that can be useful if you're into doing developer type things like
debugging the syntax trees.

cli/Cargo.toml

@@ -22,6 +22,10 @@ path = "src/main.rs"
 # to work fine in Linux.
 profiling = ["pprof"]
 
+# Enable the "debug" command. Calling it "developer" here because calling it
+# "debug" is confusing as that implies a debug build.
+developer = []
+
 # When this feature is enabled the CLI program prints debug logs if
 # the RUST_LOG environment variable is set to any of the debug levels:
 #

cli/src/commands/debug.rs

@@ -1,3 +1,4 @@
+#![cfg(feature = "developer")]
 use std::fs;
 use std::path::PathBuf;
 
@@ -47,7 +48,6 @@ pub fn debug() -> Command {
     super::command("debug")
         .about("Debug utilities")
         .arg_required_else_help(true)
-        .hide(true)
         .subcommand(ast())
         .subcommand(cst())
         .subcommand(wasm())

cli/src/commands/mod.rs

@@ -10,6 +10,7 @@ mod scan;
 pub use check::*;
 pub use compile::*;
 pub use completion::*;
+#[cfg(feature = "developer")]
 pub use debug::*;
 pub use dump::*;
 pub use fix::*;
@@ -54,6 +55,7 @@ pub fn cli() -> Command {
             commands::scan(),
             commands::compile(),
             commands::check(),
+            #[cfg(feature = "developer")]
             commands::debug(),
             commands::dump(),
             commands::fmt(),

cli/src/main.rs

@@ -56,6 +56,7 @@ fn main() -> anyhow::Result<()> {
     }));
 
     let result = match args.subcommand() {
+        #[cfg(feature = "developer")]
         Some(("debug", args)) => commands::exec_debug(args),
         Some(("check", args)) => commands::exec_check(args),
         Some(("fix", args)) => commands::exec_fix(args),