message: expand RUSTC_WRAPPER docs
diff: @@ -361,7 +361,8 @@ Sets the executable to use for `rustc`.
  * Environment: `CARGO_BUILD_RUSTC_WRAPPER` or `RUSTC_WRAPPER`
  Sets a wrapper to execute instead of `rustc`. The first argument passed to the
  -wrapper is the path to the actual `rustc`.
  +wrapper is the path to the actual executable to use
  +(i.e., `build.rustc`, if that is set, or `"rustc"` otherwise).
  ##### `build.rustc-workspace-wrapper`
  * Type: string (program path)
  @@ -369,7 +370,8 @@ wrapper is the path to the actual `rustc`.
  * Environment: `CARGO_BUILD_RUSTC_WORKSPACE_WRAPPER` or `RUSTC_WORKSPACE_WRAPPER`
  Sets a wrapper to execute instead of `rustc`, for workspace members only.
  -The first argument passed to the wrapper is the path to the actual `rustc`.
  +The first argument passed to the wrapper is the path to the actual
  +executable to use (i.e., `build.rustc`, if that is set, or `"rustc"` otherwise).
  It affects the filename hash so that artifacts produced by the wrapper are cached separately.
  ##### `build.rustdoc`
  