bootstrap: support ./x check run-make-support

src/bootstrap/src/core/build_steps/check.rs

@@ -491,6 +491,11 @@ tool_check_step!(MiroptTestTools { path: "src/tools/miropt-test-tools" });
 tool_check_step!(TestFloatParse { path: "src/etc/test-float-parse" });
 
 tool_check_step!(Bootstrap { path: "src/bootstrap", default: false });
+
+// `run-make-support` will be built as part of suitable run-make compiletest test steps, but support
+// check to make it easier to work on.
+tool_check_step!(RunMakeSupport { path: "src/tools/run-make-support", default: false });
+
 // Compiletest is implicitly "checked" when it gets built in order to run tests,
 // so this is mainly for people working on compiletest to run locally.
 tool_check_step!(Compiletest { path: "src/tools/compiletest", default: false });

src/bootstrap/src/core/builder/mod.rs

@@ -909,6 +909,7 @@ impl<'a> Builder<'a> {
                 check::RustAnalyzer,
                 check::TestFloatParse,
                 check::Bootstrap,
+                check::RunMakeSupport,
                 check::Compiletest,
             ),
             Kind::Test => describe!(