DiagnoseParser emits spurious "insert ':: IdentifierOrNew' to complete Expression" alongside the real "insert ';'" recovery

### Summary

When a statement is missing its trailing semicolon and ends in a bare `Name`, `DiagnoseParser` reports **two** `ParsingErrorInsertToComplete` (id `1610612976`) problems at the same location: the correct `insert ";" to complete Statement`, plus a spurious `insert ":: IdentifierOrNew" to complete Expression`. The second message is confusing because it suggests the user intended a method reference (`name::foo` / `name::new`) when they simply forgot a `;`.

### Steps to reproduce

```java
public class Dog {
String name;
int age;
String color;

public Dog(String name, int age, String color) {
this.name = name;
this.age = age;
this.color = color // missing ';'
}
}
```

### Actual diagnostics (both at `color`, both id 1610612976)

- `Syntax error, insert ":: IdentifierOrNew" to complete Expression`
- `Syntax error, insert ";" to complete Statement`

### Expected

Only the actionable `insert ";" to complete Statement` should be reported. The trailing `Name` is a valid prefix of a `ReferenceExpression` (`Name '::' IdentifierOrNew`, see [java.g](https://github.com/eclipse-jdt/eclipse.jdt.core/blob/master/org.eclipse.jdt.core.compiler.batch/grammar/java.g)), so the recovery engine's insertion phase scores the method-reference completion as a viable repair and emits it next to the semicolon fix.

### Notes

Same class of over-eager `DiagnoseParser` recovery as #1734 (spurious string-template recovery). Originally surfaced via VS Code: microsoft/vscode-java-pack#89.

### Environment

- Reproduces in current ECJ / Eclipse JDT and in `redhat.java` (JDT-LS).

Reproduce the diagnostic with the Java example, then read java.g and the DiagnoseParser insertion phase to see why ReferenceExpression recovery is emitted alongside the semicolon repair. Done means the missing-semicolon case reports only insert ";" to complete Statement, with coverage for the reported input.

Written by the indexing model from the issue text.