build: update llvm to 21.1.4 (#292)

include/AST/Resolver.h

@@ -45,7 +45,14 @@ public:
     }
 
     lookup_result lookup(const clang::DependentTemplateSpecializationType* type) {
-        return lookup(type->getQualifier(), type->getIdentifier());
+        auto& template_name = type->getDependentTemplateName();
+        auto identifier = template_name.getName().getIdentifier();
+        if(identifier) {
+            return lookup(template_name.getQualifier(), identifier);
+        } else {
+            /// FIXME: Operators does't have a name.
+            return {};
+        }
     }
 
     lookup_result lookup(const clang::DependentScopeDeclRefExpr* expr) {

include/AST/Semantic.h

@@ -627,7 +627,6 @@ public:
             }
 
             case clang::NestedNameSpecifier::TypeSpec:
-            case clang::NestedNameSpecifier::TypeSpecWithTemplate:
             case clang::NestedNameSpecifier::Global:
             case clang::NestedNameSpecifier::Super: {
                 break;

include/Compiler/Diagnostic.h

@@ -75,7 +75,8 @@ struct Diagnostic {
     /// The error message of this diagnostic.
     std::string message;
 
-    static DiagnosticCollector* create(std::shared_ptr<std::vector<Diagnostic>> diagnostics);
+    static std::unique_ptr<DiagnosticCollector>
+        create(std::shared_ptr<std::vector<Diagnostic>> diagnostics);
 };
 
 }  // namespace clice

include/Support/FileSystem.h

@@ -39,15 +39,15 @@ using namespace llvm::sys::fs;
 
 inline std::string resource_dir = "";
 
-inline std::expected<void, std::error_code> init_resource_dir(llvm::StringRef execute) {
+inline std::expected<void, std::string> init_resource_dir(llvm::StringRef execute) {
     llvm::SmallString<128> path;
     path::append(path, path::parent_path(execute), "..");
-    path::append(path, "lib", "clang", "20");
+    path::append(path, "lib", "clang", "21");
     if(auto error = real_path(path, path)) {
-        return std::unexpected(error);
+        return std::unexpected(std::format("{}:{}", error, path.str()));
     }
     resource_dir = path.str();
-    return std::expected<void, std::error_code>();
+    return std::expected<void, std::string>();
 }
 
 inline std::expected<std::string, std::error_code> createTemporaryFile(llvm::StringRef prefix,