Add src/tools/x to the main workspace

The original reason to exclude it was so it could run before submodules
were initialized. However, those have all been converted to subtrees
now, so the entire workspace is always ready to go.

Cargo.lock

@@ -6438,6 +6438,10 @@ version = "0.5.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1e9df38ee2d2c3c5948ea468a8406ff0db0b29ae1ffde1bcf20ef305bcc95c51"
 
+[[package]]
+name = "x"
+version = "0.1.1"
+
 [[package]]
 name = "xattr"
 version = "1.4.0"

Cargo.toml

@@ -45,6 +45,7 @@ members = [
   "src/tools/coverage-dump",
   "src/tools/wasm-component-ld",
   "src/tools/features-status-dump",
+  "src/tools/x",
 ]
 
 exclude = [
@@ -55,11 +56,6 @@ exclude = [
   "tests/rustdoc-gui",
   # HACK(eddyb) This hardcodes the fact that our CI uses `/checkout/obj`.
   "obj",
-  # The `x` binary is a thin wrapper that calls `x.py`, which initializes
-  # submodules, before which workspace members cannot be invoked because
-  # not all `Cargo.toml` files are available, so we exclude the `x` binary,
-  # so it can be invoked before the current checkout is set up.
-  "src/tools/x",
 ]
 
 [profile.release.package.rustc-rayon-core]

src/tools/tidy/src/deps.rs

@@ -81,7 +81,6 @@
     ("src/tools/rust-analyzer", EXCEPTIONS_RUST_ANALYZER, None, &[]),
     ("src/tools/rustbook", EXCEPTIONS_RUSTBOOK, None, &["src/doc/book", "src/doc/reference"]),
     ("src/tools/rustc-perf", EXCEPTIONS_RUSTC_PERF, None, &["src/tools/rustc-perf"]),
-    ("src/tools/x", &[], None, &[]),
     // tidy-alphabetical-end
 ];
 

src/tools/x/Cargo.lock

@@ -1,7 +0,0 @@
-# This file is automatically @generated by Cargo.
-# It is not intended for manual editing.
-version = 3
-
-[[package]]
-name = "x"
-version = "0.1.1"