add TestFloatParse to tools.rs for bootstrap

src/bootstrap/src/core/build_steps/test.rs

@@ -3549,9 +3549,7 @@ impl Step for TestFloatParse {
         let path = self.path.to_str().unwrap();
         let crate_name = self.path.components().last().unwrap().as_os_str().to_str().unwrap();
 
-        if !builder.download_rustc() {
-            builder.ensure(compile::Std::new(compiler, self.host));
-        }
+        builder.ensure(tool::TestFloatParse { host: self.host });
 
         // Run any unit tests in the crate
         let cargo_test = tool::prepare_tool_cargo(

src/bootstrap/src/core/build_steps/tool.rs

@@ -1096,6 +1096,38 @@ tool_extended!((self, builder),
     Rustfmt, "src/tools/rustfmt", "rustfmt", stable=true, add_bins_to_sysroot = ["rustfmt", "cargo-fmt"];
 );
 
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct TestFloatParse {
+    pub host: TargetSelection,
+}
+
+impl Step for TestFloatParse {
+    type Output = ();
+    const ONLY_HOSTS: bool = true;
+    const DEFAULT: bool = false;
+
+    fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
+        run.path("src/etc/test-float-parse")
+    }
+
+    fn run(self, builder: &Builder<'_>) {
+        let bootstrap_host = builder.config.build;
+        let compiler = builder.compiler(builder.top_stage, bootstrap_host);
+
+        builder.ensure(ToolBuild {
+            compiler,
+            target: bootstrap_host,
+            tool: "test-float-parse",
+            mode: Mode::ToolStd,
+            path: "src/etc/test-float-parse",
+            source_type: SourceType::InTree,
+            extra_features: Vec::new(),
+            allow_features: "",
+            cargo_args: Vec::new(),
+        });
+    }
+}
+
 impl Builder<'_> {
     /// Gets a `BootstrapCommand` which is ready to run `tool` in `stage` built for
     /// `host`.