Migrate `run-make/dep-graph` to `rmake.rs`

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -25,7 +25,6 @@ run-make/cross-lang-lto-upstream-rlibs/Makefile
 run-make/cross-lang-lto/Makefile
 run-make/debug-assertions/Makefile
 run-make/debugger-visualizer-dep-info/Makefile
-run-make/dep-graph/Makefile
 run-make/dep-info-doesnt-run-much/Makefile
 run-make/dep-info-spaces/Makefile
 run-make/dep-info/Makefile

tests/run-make/dep-graph/Makefile

@@ -1,12 +0,0 @@
-include ../tools.mk
-
-# ignore-cross-compile
-
-# Just verify that we successfully run and produce dep graphs when requested.
-
-all:
-	RUST_DEP_GRAPH=$(TMPDIR)/dep-graph $(RUSTC) \
-        -Cincremental=$(TMPDIR)/incr \
-        -Zquery-dep-graph -Zdump-dep-graph foo.rs
-	test -f $(TMPDIR)/dep-graph.txt
-	test -f $(TMPDIR)/dep-graph.dot

tests/run-make/dep-graph/rmake.rs

@@ -0,0 +1,18 @@
+// Just verify that we successfully run and produce dep graphs when requested.
+
+//@ ignore-cross-compile
+
+use run_make_support::{path, rustc};
+
+fn main() {
+    rustc()
+        .input("foo.rs")
+        .incremental(path("incr"))
+        .arg("-Zquery-dep-graph")
+        .arg("-Zdump-dep-graph")
+        .env("RUST_DEP_GRAPH", path("dep-graph"))
+        .run();
+
+    assert!(path("dep-graph.txt").is_file());
+    assert!(path("dep-graph.dot").is_file());
+}