Move /src/test to /tests

tests/ui/proc-macro/span-from-proc-macro.rs

@@ -0,0 +1,17 @@
+// aux-build:custom-quote.rs
+// aux-build:span-from-proc-macro.rs
+// compile-flags: -Z macro-backtrace
+
+#[macro_use]
+extern crate span_from_proc_macro;
+
+#[error_from_attribute] //~ ERROR cannot find type `MissingType`
+struct ShouldBeRemoved;
+
+#[derive(ErrorFromDerive)] //~ ERROR cannot find type `OtherMissingType`
+struct Kept;
+
+fn main() {
+    error_from_bang!(); //~ ERROR mismatched types
+    other_error_from_bang!(); //~ ERROR cannot find value `my_ident`
+}