[Sema] Use llvm::iterator_range::empty (NFC) (#151852)

Author: kazutakahirata

clang/lib/Sema/AnalysisBasedWarnings.cpp

@@ -581,7 +581,7 @@ static ControlFlowKind CheckFallThrough(AnalysisDeclContext &AC) {
     // mark them as live.
     for (const auto *B : *cfg) {
       if (!live[B->getBlockID()]) {
-        if (B->pred_begin() == B->pred_end()) {
+        if (B->preds().empty()) {
           const Stmt *Term = B->getTerminatorStmt();
           if (isa_and_nonnull<CXXTryStmt>(Term))
             // When not adding EH edges from calls, catch clauses

clang/lib/Sema/SemaDecl.cpp

@@ -5255,8 +5255,8 @@ Decl *Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS,
   if (getLangOpts().CPlusPlus &&
       DS.getStorageClassSpec() != DeclSpec::SCS_typedef)
     if (EnumDecl *Enum = dyn_cast_or_null<EnumDecl>(Tag))
-      if (Enum->enumerator_begin() == Enum->enumerator_end() &&
-          !Enum->getIdentifier() && !Enum->isInvalidDecl())
+      if (Enum->enumerators().empty() && !Enum->getIdentifier() &&
+          !Enum->isInvalidDecl())
         DeclaresAnything = false;
 
   if (!DS.isMissingDeclaratorOk()) {

clang/lib/Sema/SemaExpr.cpp

@@ -6523,8 +6523,7 @@ ExprResult Sema::ActOnCallExpr(Scope *Scope, Expr *Fn, SourceLocation LParenLoc,
   // Diagnose uses of the C++20 "ADL-only template-id call" feature in earlier
   // language modes.
   if (const auto *ULE = dyn_cast<UnresolvedLookupExpr>(Fn);
-      ULE && ULE->hasExplicitTemplateArgs() &&
-      ULE->decls_begin() == ULE->decls_end()) {
+      ULE && ULE->hasExplicitTemplateArgs() && ULE->decls().empty()) {
     DiagCompat(Fn->getExprLoc(), diag_compat::adl_only_template_id)
         << ULE->getName();
   }

clang/lib/Sema/SemaInit.cpp

@@ -4836,7 +4836,7 @@ static void TryReferenceListInitialization(Sema &S,
     }
 
     // Update the initializer if we've resolved an overloaded function.
-    if (Sequence.step_begin() != Sequence.step_end())
+    if (!Sequence.steps().empty())
       Sequence.RewrapReferenceInitList(cv1T1, InitList);
   }
   // Perform address space compatibility check.

clang/lib/Sema/SemaLookup.cpp

@@ -3130,7 +3130,7 @@ addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
         CollectEnclosingNamespace(Result.Namespaces, BaseCtx);
 
         // Make sure we visit the bases of this base class.
-        if (BaseDecl->bases_begin() != BaseDecl->bases_end())
+        if (!BaseDecl->bases().empty())
           Bases.push_back(BaseDecl);
       }
     }