tests/run-make/crate-loading: Rename source files for clarity

To make the code easier to understand.

Author: Enselic

tests/run-make/crate-loading/multiple-dep-versions-3.rs renamed to tests/run-make/crate-loading/dep-2-reexport.rs

@@ -6,12 +6,9 @@
 use run_make_support::{diff, rust_lib_name, rustc};
 
 fn main() {
-    rustc().input("multiple-dep-versions-1.rs").run();
-    rustc().input("multiple-dep-versions-2.rs").extra_filename("2").metadata("2").run();
-    rustc()
-        .input("multiple-dep-versions-3.rs")
-        .extern_("dependency", rust_lib_name("dependency2"))
-        .run();
+    rustc().input("dependency-1.rs").run();
+    rustc().input("dependency-2.rs").extra_filename("2").metadata("2").run();
+    rustc().input("dep-2-reexport.rs").extern_("dependency", rust_lib_name("dependency2")).run();
 
     let out = rustc()
         .input("multiple-dep-versions.rs")