[clang] Migrate away from a deprecated Clang CFG factory function

clang-tools-extra/clang-tidy/bugprone/UncheckedOptionalAccessCheck.cpp

 static Optional<std::vector<SourceLocation>>
 analyzeFunction(const FunctionDecl &FuncDecl, ASTContext &ASTCtx,
                 UncheckedOptionalAccessModelOptions ModelOptions) {
   using dataflow::ControlFlowContext;
   using dataflow::DataflowAnalysisState;
   using llvm::Expected;
 
   Expected<ControlFlowContext> Context =
-      ControlFlowContext::build(&FuncDecl, FuncDecl.getBody(), &ASTCtx);
+      ControlFlowContext::build(&FuncDecl, *FuncDecl.getBody(), ASTCtx);
   if (!Context)
     return std::nullopt;
 
   dataflow::DataflowAnalysisContext AnalysisContext(
       std::make_unique<dataflow::WatchedLiteralsSolver>());
   dataflow::Environment Env(AnalysisContext, FuncDecl);
   UncheckedOptionalAccessModel Analysis(ASTCtx);
   UncheckedOptionalAccessDiagnoser Diagnoser(ModelOptions);

clang/unittests/Analysis/FlowSensitive/TypeErasedDataflowAnalysisTest.cpp

auto *Func = selectFirst<FunctionDecl>(
       "func", match(functionDecl(ast_matchers::hasName("target")).bind("func"),
                     AST->getASTContext()));
   assert(Func != nullptr);
 
   Stmt *Body = Func->getBody();
   assert(Body != nullptr);
 
   auto CFCtx = llvm::cantFail(
-      ControlFlowContext::build(nullptr, Body, &AST->getASTContext()));
+      ControlFlowContext::build(nullptr, *Body, AST->getASTContext()));
 
   AnalysisT Analysis = MakeAnalysis(AST->getASTContext());
   DataflowAnalysisContext DACtx(std::make_unique<WatchedLiteralsSolver>());
   Environment Env(DACtx);
 
   return runDataflowAnalysis(CFCtx, Analysis, Env);
 }