Better handle too many # recovery in raw str

Point at all the unnecessary trailing `#`.
Better handle interaction with outer attributes when `;` is missing.

Fix #95030.

src/test/ui/parser/raw/raw-str-unbalanced.rs

@@ -1,4 +1,22 @@
 static s: &'static str =
-    r#"
-      "## //~ too many `#` when terminating raw string
+    r#""## //~ ERROR too many `#` when terminating raw string
 ;
+
+static s2: &'static str =
+    r#"
+      "#### //~ ERROR too many `#` when terminating raw string
+;
+
+const A: &'static str = r"" //~ ERROR expected `;`, found `#`
+
+// Test
+#[test]
+fn test() {}
+
+const B: &'static str = r""## //~ ERROR too many `#` when terminating raw string
+
+// Test
+#[test]
+fn test2() {}
+
+fn main() {}

src/test/ui/parser/raw/raw-str-unbalanced.stderr

@@ -1,10 +1,36 @@
 error: too many `#` when terminating raw string
-  --> $DIR/raw-str-unbalanced.rs:3:9
+  --> $DIR/raw-str-unbalanced.rs:2:10
    |
-LL |       "##
-   |         ^ help: remove the extra `#`
+LL |     r#""##
+   |     -----^ help: remove the extra `#`
+   |     |
+   |     this raw string started with 1 `#`
+
+error: too many `#` when terminating raw string
+  --> $DIR/raw-str-unbalanced.rs:7:9
    |
-   = note: the raw string started with 1 `#`s
+LL | /     r#"
+LL | |       "####
+   | |        -^^^ help: remove the extra `#`s
+   | |________|
+   |          this raw string started with 1 `#`
 
-error: aborting due to previous error
+error: expected `;`, found `#`
+  --> $DIR/raw-str-unbalanced.rs:10:28
+   |
+LL | const A: &'static str = r""
+   |                            ^ help: add `;` here
+...
+LL | #[test]
+   | - unexpected token
+
+error: too many `#` when terminating raw string
+  --> $DIR/raw-str-unbalanced.rs:16:28
+   |
+LL | const B: &'static str = r""##
+   |                         ---^^ help: remove the extra `#`s
+   |                         |
+   |                         this raw string started with 0 `#`s
+
+error: aborting due to 4 previous errors