Apply --cfg windows_raw_dylib for bootstrap tools too

This is already applied for rustc/std tools. This is needed to make
`windows` crates avoid trying to depend on a generated
`windows.0.xx.0.lib`.

src/bootstrap/src/core/builder/cargo.rs

@@ -597,7 +597,7 @@ fn cargo(
         // sysroot. Passing this cfg enables raw-dylib support instead, which makes the native
         // library unnecessary. This can be removed when windows-rs enables raw-dylib
         // unconditionally.
-        if let Mode::Rustc | Mode::ToolRustc = mode {
+        if let Mode::Rustc | Mode::ToolRustc | Mode::ToolBootstrap = mode {
             rustflags.arg("--cfg=windows_raw_dylib");
         }