LibLine: Handle interrupts again

This commit makes LibLine handle interrupts (as reported via
interrupted() and resized()) again.
There is a little catch with the shell:
```
$     ls |
pipe> <C-c> (prompt stays here until a key is pressed)
```

2 files changed, 30 insertions, 14 deletions

diff --git a/Libraries/LibLine/Editor.cpp b/Libraries/LibLine/Editor.cpp
index 2fe2900429..697f6f3634 100644
--- a/Libraries/LibLine/Editor.cpp
+++ b/Libraries/LibLine/Editor.cpp
@@ -292,6 +292,9 @@ auto Editor::get_line(const String& prompt) -> Result<String, Editor::Error>
     add_child(*m_notifier);
 
     m_notifier->on_ready_to_read = [&] {
+        if (m_was_interrupted)
+            handle_interrupt_event();
+
         handle_read_event();
 
         if (m_always_refresh)
@@ -342,6 +345,23 @@ void Editor::save_to(JsonObject& object)
     object.set("used_display_area", move(display_area));
 }
 
+void Editor::handle_interrupt_event()
+{
+    m_was_interrupted = false;
+
+    if (!m_buffer.is_empty())
+        printf("^C");
+
+    m_buffer.clear();
+    m_cursor = 0;
+
+    if (on_interrupt_handled)
+        on_interrupt_handled();
+
+    m_refresh_needed = true;
+    refresh_display();
+}
+
 void Editor::handle_read_event()
 {
     char keybuf[16];
@@ -360,18 +380,7 @@ void Editor::handle_read_event()
                 return;
             }
 
-            m_was_interrupted = false;
-
-            if (!m_buffer.is_empty())
-                printf("^C");
-
-            m_buffer.clear();
-            m_cursor = 0;
-
-            if (on_interrupt_handled)
-                on_interrupt_handled();
-
-            m_refresh_needed = true;
+            handle_interrupt_event();
             return;
         }
 
diff --git a/Libraries/LibLine/Editor.h b/Libraries/LibLine/Editor.h
index c3f8db1cb7..3ebb9e1d52 100644
--- a/Libraries/LibLine/Editor.h
+++ b/Libraries/LibLine/Editor.h
@@ -114,10 +114,16 @@ public:
     // since we can not do this cleanly ourselves. (signal() limitation: cannot give member functions)
     void interrupted()
     {
-        if (m_is_editing)
+        if (m_is_editing) {
             m_was_interrupted = true;
+            handle_interrupt_event();
+        }
+    }
+    void resized()
+    {
+        m_was_resized = true;
+        refresh_display();
     }
-    void resized() { m_was_resized = true; }
 
     size_t cursor() const { return m_cursor; }
     const Vector<u32, 1024>& buffer() const { return m_buffer; }
@@ -176,6 +182,7 @@ private:
         Function<bool(Editor&)> callback;
     };
 
+    void handle_interrupt_event();
     void handle_read_event();
 
     Vector<size_t, 2> vt_dsr();