LibCore: Add support for range-based for loops on LineIterators

Userland/Libraries/LibCore/IODevice.cpp

@@ -319,4 +319,8 @@ LineIterator& LineIterator::operator++()
     m_buffer = m_device->read_line();
     return *this;
 }
+
+LineIterator LineRange::begin() { return m_device.line_begin(); }
+LineIterator LineRange::end() { return m_device.line_end(); }
+
 }

Userland/Libraries/LibCore/IODevice.h

@@ -12,6 +12,8 @@
 
 namespace Core {
 
+class IODevice;
+
 // This is not necessarily a valid iterator in all contexts,
 // if we had concepts, this would be InputIterator, not Copyable, Movable.
 class LineIterator {
@@ -34,6 +36,20 @@ private:
     String m_buffer;
 };
 
+class LineRange {
+public:
+    LineRange() = delete;
+    explicit LineRange(IODevice& device)
+        : m_device(device)
+    {
+    }
+    LineIterator begin();
+    LineIterator end();
+
+private:
+    IODevice& m_device;
+};
+
 enum class OpenMode : unsigned {
     NotOpen = 0,
     ReadOnly = 1,
@@ -91,6 +107,10 @@ public:
 
     LineIterator line_begin() & { return LineIterator(*this); }
     LineIterator line_end() { return LineIterator(*this, true); }
+    LineRange lines()
+    {
+        return LineRange(*this);
+    }
 
 protected:
     explicit IODevice(Object* parent = nullptr);