[clang] [clang][dataflow] Expose getReferencedDecls and relocate free functions. (PR #88754)

[via cfe-commits]

================
@@ -648,36 +563,13 @@ void Environment::initialize() {
 void Environment::initFieldsGlobalsAndFuncs(const FunctionDecl *FuncDecl) {
   assert(FuncDecl->doesThisDeclarationHaveABody());
 
-  FieldSet Fields;
-  llvm::DenseSet<const VarDecl *> Vars;
-  llvm::DenseSet<const FunctionDecl *> Funcs;
-
-  // Look for global variable and field references in the
-  // constructor-initializers.
-  if (const auto *CtorDecl = dyn_cast<CXXConstructorDecl>(FuncDecl)) {
-    for (const auto *Init : CtorDecl->inits()) {
-      if (Init->isMemberInitializer()) {
-        Fields.insert(Init->getMember());
-      } else if (Init->isIndirectMemberInitializer()) {
-        for (const auto *I : Init->getIndirectMember()->chain())
-          Fields.insert(cast<FieldDecl>(I));
-      }
-      const Expr *E = Init->getInit();
-      assert(E != nullptr);
-      getFieldsGlobalsAndFuncs(*E, Fields, Vars, Funcs);
-    }
-    // Add all fields mentioned in default member initializers.
-    for (const FieldDecl *F : CtorDecl->getParent()->fields())
-      if (const auto *I = F->getInClassInitializer())
-          getFieldsGlobalsAndFuncs(*I, Fields, Vars, Funcs);
-  }
-  getFieldsGlobalsAndFuncs(*FuncDecl->getBody(), Fields, Vars, Funcs);
+  ReferencedDecls FGF = getReferencedDecls(*FuncDecl);
----------------
martinboehme wrote:

```suggestion
  ReferencedDecls Referenced = getReferencedDecls(*FuncDecl);
```

(Now that the struct is called `ReferencedDecls`, it's not clear why the variable should be called `FGF`.)

https://github.com/llvm/llvm-project/pull/88754