docs: doc comments typo fixes

Author: weihanglo

src/cargo/core/features.rs

@@ -27,7 +27,7 @@
 //!   * Good for: `.cargo/config.toml`, `config.json` index file (gate: `-Z`)
 //!
 //! For features that touch multiple parts of Cargo, multiple feature gating strategies (error,
-//! warn, ignore) and mechnisms (`-Z`, `cargo-features`) may be used.
+//! warn, ignore) and mechanisms (`-Z`, `cargo-features`) may be used.
 //!
 //! When adding new tests for your feature, usually the tests should go into a
 //! new module of the testsuite named after the feature. See
@@ -513,7 +513,7 @@ features! {
 
 /// Status and metadata for a single unstable feature.
 pub struct Feature {
-    /// Feature name. This is valid Rust identifer so no dash only underscore.
+    /// Feature name. This is valid Rust identifier so no dash only underscore.
     name: &'static str,
     stability: Status,
     /// Version that this feature was stabilized or removed.

src/cargo/sources/registry/mod.rs

@@ -967,7 +967,7 @@ impl RegistryConfig {
     const NAME: &'static str = "config.json";
 }
 
-/// Get the maximum upack size that Cargo permits
+/// Get the maximum unpack size that Cargo permits
 /// based on a given `size` of your compressed file.
 ///
 /// Returns the larger one between `size * max compression ratio`

src/cargo/util/cache_lock.rs

@@ -513,7 +513,7 @@ impl CacheLocker {
     ///
     /// Note that `Shared` will return true if a `MutateExclusive` lock is
     /// held, since `MutateExclusive` is just an upgraded `Shared`. Likewise,
-    /// `DownlaodExclusive` will return true if a `MutateExclusive` lock is
+    /// `DownloadExclusive` will return true if a `MutateExclusive` lock is
     /// held since they overlap.
     pub fn is_locked(&self, mode: CacheLockMode) -> bool {
         let state = self.state.borrow();