Debugger: Remove widget argument from tooltip request

The only information ever used is whether it's c++ or not.

Change-Id: I4ca00663856dd66cbdf58c468f175a8c9e41d6a5
Reviewed-by: hjk <hjk@theqtcompany.com>

src/plugins/debugger/sourceutils.h

@@ -40,7 +40,6 @@ namespace Debugger {
 namespace Internal {
 
 // Editor tooltip support
-bool isCppEditor(TextEditor::TextEditorWidget *editorWidget);
 QString cppExpressionAt(TextEditor::TextEditorWidget *editorWidget, int pos,
                         int *line, int *column, QString *function = 0,
                         int *scopeFromLine = 0, int *scopeToLine = 0);