convert simple-dylib to ui test

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -235,7 +235,6 @@ run-make/share-generics-dylib/Makefile
 run-make/short-ice/Makefile
 run-make/silly-file-names/Makefile
 run-make/simd-ffi/Makefile
-run-make/simple-dylib/Makefile
 run-make/split-debuginfo/Makefile
 run-make/stable-symbol-names/Makefile
 run-make/static-dylib-by-default/Makefile

tests/run-make/simple-dylib/Makefile

@@ -1,6 +0,0 @@
-# ignore-cross-compile
-include ../tools.mk
-all:
-	$(RUSTC) bar.rs --crate-type=dylib -C prefer-dynamic
-	$(RUSTC) foo.rs
-	$(call RUN,foo)

tests/run-make/simple-dylib/bar.rs

@@ -1 +0,0 @@
-pub fn bar() {}

tests/run-make/simple-dylib/foo.rs

@@ -1,5 +0,0 @@
-extern crate bar;
-
-fn main() {
-    bar::bar();
-}

tests/ui/imports/auxiliary/simple-dylib.rs

@@ -0,0 +1,4 @@
+//@ compile-flags --crate-type=dylib -Cprefer-dynamic
+
+#![crate_type = "dylib"]
+pub fn bar() {}

tests/ui/imports/simple-dylib-import.rs

@@ -0,0 +1,12 @@
+// A simple test, where foo.rs has a dependency
+// on the dynamic library simple-dylib.rs. If the test passes,
+// dylibs can be built and linked into another file successfully..
+
+//@ aux-crate: simple-dylib.rs
+//@ run-pass
+
+extern crate bar;
+
+fn main() {
+    bar::bar();
+}