[LIBCLC] Use default compilation DB for ClangTool run (#9974)

Since
94f7c96
landed the `-fno-lifetime-dse` option is added to the compilation
database, if using non-llvm based toolchains, this option is not
compatible with clang and as tools invocation in libclc does not relay
on the content of the DB, use the default, empty one.

Also fix deprecated `makeArrayRef` warning.

cc: [abagusetty](https://github.com/abagusetty)

Author: Jakub Chlanda

libclc/utils/libclc-remangler/LibclcRemangler.cpp

@@ -449,8 +449,7 @@ class Remangler {
     auto *FTD = FunctionTemplateDecl::Create(*AST, FD->getDeclContext(),
                                              SourceLocation(),
                                              DeclarationName(), TPL, FD);
-    auto TAArr =
-        makeArrayRef(TemplateArguments.begin(), TemplateArguments.size());
+    auto TAArr = ArrayRef(TemplateArguments.begin(), TemplateArguments.size());
     auto *TAL = TemplateArgumentList::CreateCopy(*AST, TAArr);
     FDSpecialization->setTemplateParameterListsInfo(*AST, TPL);
     FDSpecialization->setFunctionTemplateSpecialization(
@@ -962,9 +961,10 @@ int main(int argc, const char **argv) {
     return 1;
   }
 
-  CommonOptionsParser &OptionsParser = ExpectedParser.get();
-  ClangTool Tool(OptionsParser.getCompilations(),
-                 OptionsParser.getSourcePathList());
+  // Use a default Compilation DB instead of the build one, as it might contain
+  // toolchain specific options, not compatible with clang.
+  FixedCompilationDatabase Compilations("/", std::vector<std::string>());
+  ClangTool Tool(Compilations, ExpectedParser->getSourcePathList());
 
   LibCLCRemanglerActionFactory LRAF{};
   std::unique_ptr<FrontendActionFactory> FrontendFactory;