[compiler] Use ElementSizeInPointers

Small refactoring to use an existing ElementSizeInPointers (which has
the same implementation). LinkageLocation::GetSize is now not called
anywhere else, so remove it. The instruction selector can then call
LinkageLocation::GetSizeInPointers instead of calculating it.

Bug: v8:11879
Change-Id: I6f717db1c4047e7847f00cf2bf96c6ec8ea52bda
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2997924Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75520}

src/compiler/backend/instruction-selector.cc

@@ -1154,9 +1154,7 @@ void InstructionSelector::InitializeCallBuffer(Node* call, CallBuffer* buffer,
       // This can insert empty slots before stack_index and will insert enough
       // slots after stack_index to store the parameter.
       if (static_cast<size_t>(stack_index) >= buffer->pushed_nodes.size()) {
-        int num_slots = std::max(
-            1, (ElementSizeInBytes(location.GetType().representation()) /
-                kSystemPointerSize));
+        int num_slots = location.GetSizeInPointers();
         buffer->pushed_nodes.resize(stack_index + num_slots);
       }
       PushParameter param = {*iter, location};

src/compiler/linkage.h

@@ -127,13 +127,8 @@ class LinkageLocation {
 
   MachineType GetType() const { return machine_type_; }
 
-  int GetSize() const {
-    return 1 << ElementSizeLog2Of(GetType().representation());
-  }
-
   int GetSizeInPointers() const {
-    // Round up
-    return (GetSize() + kSystemPointerSize - 1) / kSystemPointerSize;
+    return ElementSizeInPointers(GetType().representation());
   }
 
   int32_t GetLocation() const {