More raw string tests

Author: rcoh

src/test/ui/parser/raw/raw-string-2.rs

@@ -0,0 +1,4 @@
+fn main() {
+    let x = r###"here's a long string"# "# "##;
+    //~^ ERROR unterminated raw string
+}

src/test/ui/parser/raw/raw-string-2.stderr

@@ -0,0 +1,11 @@
+error[E0748]: unterminated raw string
+  --> $DIR/raw-string-2.rs:2:13
+   |
+LL |     let x = r###"here's a long string"# "# "##;
+   |             ^ unterminated raw string       -- help: consider terminating the string here: `###`
+   |
+   = note: this raw string should be terminated with `"###`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0748`.

src/test/ui/parser/raw/raw_string.rs renamed to src/test/ui/parser/raw/raw-string.rs

@@ -1,5 +1,5 @@
 error[E0748]: unterminated raw string
-  --> $DIR/raw_string.rs:2:13
+  --> $DIR/raw-string.rs:2:13
    |
 LL |     let x = r##"lol"#;
    |             ^       - help: consider terminating the string here: `##`