[analyzer] LazyCompoundVals should be always bound as default bindings

[steakhal]

Summary

LazyCompoundVals should only appear as default bindings in the
store. This fixes the second case in this patch-stack.

Depends on: D132142

[steakhal]

• Rebase for using :digit: regex matching in the tests.

clang/lib/StaticAnalyzer/Core/RegionStore.cpp

RegionStoreManager::bind(RegionBindingsConstRef B, Loc L, SVal V) {
   if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
     R = GetElementZeroRegion(SR, SR->getApproximatedType());
 
   assert((!isa<CXXThisRegion>(R) || !B.lookup(R)) &&
          "'this' pointer is not an l-value and is not assignable");
 
   // Clear out bindings that may overlap with this binding.
   RegionBindingsRef NewB = removeSubRegionBindings(B, cast<SubRegion>(R));
-  return NewB.addBinding(BindingKey::Make(R, BindingKey::Direct), V);
+
+  // LazyCompoundVals should be always bound as 'default' bindings.
+  auto KeyKind = isa<nonloc::LazyCompoundVal>(V) ? BindingKey::Default
+                                                 : BindingKey::Direct;
+  return NewB.addBinding(BindingKey::Make(R, KeyKind), V);
 }
 
 RegionBindingsRef
 RegionStoreManager::setImplicitDefaultValue(RegionBindingsConstRef B,
                                             const MemRegion *R,
                                             QualType T) {
   SVal V;
 

clang/test/Analysis/trivial-copy-struct.cpp

 
 void copy_on_heap(Node* n1) {
   Node* n2 = new Node(*n1);
 
   clang_analyzer_dump(n1); // expected-warning {{&SymRegion{reg_$2<Node * n1>}}}
   clang_analyzer_dump(n2); // expected-warning {{&HeapSymRegion{conj_$1{Node *, LC1, S1855, #1}}}}
 
   clang_analyzer_dump(n1->ptr); // expected-warning {{&SymRegion{reg_$3<int * Element{SymRegion{reg_$2<Node * n1>},0 S64b,struct Node}.ptr>}}}
-  clang_analyzer_dump(n2->ptr); // expected-warning {{Unknown}} FIXME: This should be the same as above.
+  clang_analyzer_dump(n2->ptr); // expected-warning {{&SymRegion{reg_$3<int * Element{SymRegion{reg_$2<Node * n1>},0 S64b,struct Node}.ptr>}}}
 
   if (n1->ptr != n2->ptr)
-    clang_analyzer_warnIfReached(); // expected-warning {{REACHABLE}} FIXME: This should not be reachable.
+    clang_analyzer_warnIfReached(); // unreachable
   (void)(n1->ptr);
   (void)(n2->ptr);
 }