Add coverage for negative indices with resizable typed arrays

SpiderMonkey doesn't handle this case correctly.

test/built-ins/TypedArray/prototype/lastIndexOf/negative-index-and-resize-to-smaller.js

@@ -0,0 +1,57 @@
+// Copyright (C) 2025 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-%typedarray%.prototype.lastIndexOf
+description: >
+  Negative index is relative to the original typed array length.
+info: |
+  %TypedArray%.prototype.lastIndexOf ( searchElement [ , fromIndex ] )
+
+  ...
+  5. If fromIndex is present, let n be ? ToIntegerOrInfinity(fromIndex); else let n be len - 1.
+  6. If n = -∞, return -1𝔽.
+  7. If n ≥ 0, then
+    a. Let k be min(n, len - 1).
+  8. Else,
+    a. Let k be len + n.
+  ...
+features: [TypedArray, resizable-arraybuffer]
+includes: [testTypedArray.js]
+---*/
+
+testWithTypedArrayConstructors(function(TA) {
+  var byteLength = 4 * TA.BYTES_PER_ELEMENT;
+  var rab = new ArrayBuffer(0, {maxByteLength: byteLength});
+  var ta = new TA(rab);
+
+  var indices = [
+    [-1, 2],
+    [-2, 2],
+    [-3, 1],
+    [-4, 0],
+    [-5, -1],
+  ];
+
+  for (var i = 0; i < indices.length; ++i) {
+    var index = indices[i][0];
+    var expected = indices[i][1];
+    var searchElement = 123;
+
+    rab.resize(byteLength);
+    ta.fill(searchElement);
+
+    var indexValue = {
+      valueOf() {
+        rab.resize(3 * TA.BYTES_PER_ELEMENT);
+        return index;
+      }
+    };
+
+    assert.sameValue(
+      ta.lastIndexOf(searchElement, indexValue),
+      expected,
+      "For index " + index
+    );
+  }
+});