[clangd] Fix use-after-free in ArgStripper

Author: sam-mccall

clang-tools-extra/clangd/CompileCommands.h

@@ -12,6 +12,7 @@
 #include "clang/Tooling/ArgumentsAdjusters.h"
 #include "clang/Tooling/CompilationDatabase.h"
 #include "llvm/ADT/StringMap.h"
+#include <deque>
 #include <string>
 #include <vector>
 
@@ -92,7 +93,7 @@ class ArgStripper {
   const Rule *matchingRule(llvm::StringRef Arg, unsigned Mode,
                            unsigned &ArgCount) const;
   llvm::SmallVector<Rule, 4> Rules;
-  std::vector<std::string> Storage; // Store strings not found in option table.
+  std::deque<std::string> Storage; // Store strings not found in option table.
 };
 
 } // namespace clangd