[heap] Remove stray const from HeapObject arguments

These are ancient artefacts from when HeapObject was a pointer.

Bug: v8:9396
Change-Id: I1782837aa5bd4b8393cd084321b90baa614a7373
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1691911Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Maciej Goszczycki <goszczycki@google.com>
Cr-Commit-Position: refs/heads/master@{#62647}

src/heap/heap-inl.h

@@ -372,7 +372,7 @@ bool Heap::InToPage(HeapObject heap_object) {
 bool Heap::InOldSpace(Object object) { return old_space_->Contains(object); }
 
 // static
-Heap* Heap::FromWritableHeapObject(const HeapObject obj) {
+Heap* Heap::FromWritableHeapObject(HeapObject obj) {
   MemoryChunk* chunk = MemoryChunk::FromHeapObject(obj);
   // RO_SPACE can be shared between heaps, so we can't use RO_SPACE objects to
   // find a heap. The exception is when the ReadOnlySpace is writeable, during

src/heap/heap.h

@@ -993,7 +993,7 @@ class Heap {
   // with off-heap Addresses.
   bool InSpaceSlow(Address addr, AllocationSpace space);
 
-  static inline Heap* FromWritableHeapObject(const HeapObject obj);
+  static inline Heap* FromWritableHeapObject(HeapObject obj);
 
   // ===========================================================================
   // Object statistics tracking. ===============================================

src/heap/spaces.h

@@ -713,7 +713,7 @@ class MemoryChunk {
     return reinterpret_cast<MemoryChunk*>(BaseAddress(a));
   }
   // Only works if the object is in the first kPageSize of the MemoryChunk.
-  static MemoryChunk* FromHeapObject(const HeapObject o) {
+  static MemoryChunk* FromHeapObject(HeapObject o) {
     return reinterpret_cast<MemoryChunk*>(BaseAddress(o.ptr()));
   }
 
@@ -1145,7 +1145,7 @@ class Page : public MemoryChunk {
   static Page* FromAddress(Address addr) {
     return reinterpret_cast<Page*>(addr & ~kPageAlignmentMask);
   }
-  static Page* FromHeapObject(const HeapObject o) {
+  static Page* FromHeapObject(HeapObject o) {
     return reinterpret_cast<Page*>(o.ptr() & ~kAlignmentMask);
   }
 
@@ -1268,7 +1268,7 @@ class LargePage : public MemoryChunk {
   // x64 and ia32 architectures.
   static const int kMaxCodePageSize = 512 * MB;
 
-  static LargePage* FromHeapObject(const HeapObject o) {
+  static LargePage* FromHeapObject(HeapObject o) {
     return static_cast<LargePage*>(MemoryChunk::FromHeapObject(o));
   }