Revert "[ptr-compr] Fix --no-debug-code issue with loading JSArray::length"

This reverts commit e27b7b60, which was
a workaround. The original problem is not reproducible anymore.

Bug: v8:9717
Change-Id: I11e165d7ec9643ec805ab8c075b720b58e7769bb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2699249
Auto-Submit: Georg Neis <neis@chromium.org>
Reviewed-by: Santiago Aboy Solanes <solanes@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72803}

src/builtins/builtins-array-gen.cc

@@ -242,7 +242,9 @@ TF_BUILTIN(ArrayPrototypePop, CodeStubAssembler) {
   BIND(&fast);
   {
     TNode<JSArray> array_receiver = CAST(receiver);
-    TNode<IntPtrT> length = SmiUntag(LoadFastJSArrayLength(array_receiver));
+    CSA_ASSERT(this, TaggedIsPositiveSmi(LoadJSArrayLength(array_receiver)));
+    TNode<IntPtrT> length =
+        LoadAndUntagObjectField(array_receiver, JSArray::kLengthOffset);
     Label return_undefined(this), fast_elements(this);
 
     // 2) Ensure that the length is writable.