Add regression test for include_str! normalization

Author: matklad

src/test/ui/.gitattributes

@@ -1,2 +1,3 @@
 lexer-crlf-line-endings-string-literal-doc-comment.rs -text
 trailing-carriage-return-in-string.rs -text
+*.bin -text

src/test/ui/include-macros/data.bin

@@ -0,0 +1,2 @@
+This file starts with BOM.
+Lines are separated by \r\n.

src/test/ui/include-macros/normalization.rs

@@ -0,0 +1,12 @@
+// run-pass
+
+fn main() {
+    assert_eq!(
+        &include_bytes!("data.bin")[..],
+        &b"\xEF\xBB\xBFThis file starts with BOM.\r\nLines are separated by \\r\\n.\r\n"[..],
+    );
+    assert_eq!(
+        include_str!("data.bin"),
+        "\u{FEFF}This file starts with BOM.\r\nLines are separated by \\r\\n.\r\n",
+    );
+}