AK: Make Vector::remove_all_matching() return removal success

This matches the behavior of other remove_*_matching() functions.

AK/Vector.h

@@ -405,15 +405,18 @@ public:
     }
 
     template<typename TUnaryPredicate>
-    void remove_all_matching(TUnaryPredicate predicate)
+    bool remove_all_matching(TUnaryPredicate predicate)
     {
+        bool something_was_removed = false;
         for (size_t i = 0; i < size();) {
             if (predicate(at(i))) {
                 remove(i);
+                something_was_removed = true;
             } else {
                 ++i;
             }
         }
+        return something_was_removed;
     }
 
     ALWAYS_INLINE T take_last()

Tests/AK/TestVector.cpp

@@ -259,6 +259,29 @@ TEST_CASE(vector_remove)
     EXPECT_EQ(ints[0], 4);
 }
 
+TEST_CASE(remove_all_matching)
+{
+    Vector<int> ints;
+
+    ints.append(1);
+    ints.append(2);
+    ints.append(3);
+    ints.append(4);
+
+    EXPECT_EQ(ints.size(), 4u);
+
+    EXPECT_EQ(ints.remove_all_matching([&](int value) { return value > 2; }), true);
+    EXPECT_EQ(ints.remove_all_matching([&](int) { return false; }), false);
+
+    EXPECT_EQ(ints.size(), 2u);
+
+    EXPECT_EQ(ints.remove_all_matching([&](int) { return true; }), true);
+
+    EXPECT(ints.is_empty());
+
+    EXPECT_EQ(ints.remove_all_matching([&](int) { return true; }), false);
+}
+
 TEST_CASE(nonnullownptrvector)
 {
     struct Object {