Fix some -Wdeprecated-copy warnings.

Bug: chromium:1221591
Change-Id: Ie24334873d1e66de0e0aa90fa1fb49d4290b7b59
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2973214
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Auto-Submit: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75255}

src/compiler/node-origin-table.h

@@ -34,6 +34,7 @@ class NodeOrigin {
         created_from_(created_from) {}
 
   NodeOrigin(const NodeOrigin& other) V8_NOEXCEPT = default;
+  NodeOrigin& operator=(const NodeOrigin& other) V8_NOEXCEPT = default;
   static NodeOrigin Unknown() { return NodeOrigin(); }
 
   bool IsKnown() { return created_from_ >= 0; }

src/compiler/store-store-elimination.cc

@@ -94,6 +94,8 @@ class UnobservablesSet final {
   // can probably be optimized to use a global singleton.
   static UnobservablesSet VisitedEmpty(Zone* zone);
   UnobservablesSet(const UnobservablesSet& other) V8_NOEXCEPT = default;
+  UnobservablesSet& operator=(const UnobservablesSet& other)
+      V8_NOEXCEPT = default;
 
   // Computes the intersection of two UnobservablesSets. If one of the sets is
   // empty, will return empty.

src/zone/zone-handle-set.h

@@ -199,8 +199,8 @@ class ZoneHandleSet<T>::const_iterator {
   using reference = value_type;
   using pointer = value_type*;
 
-  const_iterator(const const_iterator& other)
-      : set_(other.set_), current_(other.current_) {}
+  const_iterator(const const_iterator& other) = default;
+  const_iterator& operator=(const const_iterator& other) = default;
 
   reference operator*() const { return (*set_)[current_]; }
   bool operator==(const const_iterator& other) const {