[wasm][cleanup] Simplify DisjointAllocationPool constructors.

R=clemensh@chromium.org

Change-Id: I4ef23446609e0b276877aedaccbd738497f2853f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1601145Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61327}

src/wasm/wasm-code-manager.h

@@ -46,15 +46,10 @@ struct WasmModule;
 // because that should have been reduced to [start, other_end).
 class V8_EXPORT_PRIVATE DisjointAllocationPool final {
  public:
-  DisjointAllocationPool() = default;
-
+  MOVE_ONLY_WITH_DEFAULT_CONSTRUCTORS(DisjointAllocationPool);
   explicit DisjointAllocationPool(base::AddressRegion region)
       : regions_({region}) {}
 
-  DisjointAllocationPool(DisjointAllocationPool&& other) V8_NOEXCEPT = default;
-  DisjointAllocationPool& operator=(DisjointAllocationPool&& other)
-      V8_NOEXCEPT = default;
-
   // Merge the parameter region into this object while preserving ordering of
   // the regions. The assumption is that the passed parameter is not
   // intersecting this object - for example, it was obtained from a previous
@@ -70,8 +65,6 @@ class V8_EXPORT_PRIVATE DisjointAllocationPool final {
 
  private:
   std::list<base::AddressRegion> regions_;
-
-  DISALLOW_COPY_AND_ASSIGN(DisjointAllocationPool);
 };
 
 class V8_EXPORT_PRIVATE WasmCode final {