[llvm] [llvm-cxxfilt] Add --quote option to quote demangled function names (PR #111871)

[Ronan Keryell via llvm-commits]

================
@@ -100,7 +99,7 @@ static std::string demangle(const std::string &Mangled, StringRef Delimiters) {
   }
 
   Result =
-      Undecorated ? Prefix + optionalQuote(Undecorated, Delimiters) : Mangled;
+      Undecorated ? optionalQuote(Prefix + Undecorated, Delimiters) : Mangled;
----------------
keryell wrote:

This was what I had first but actually to generate valid LLVM/MLIR assembly like
```mlir
%5 = cir.call @"import thunk for std::future<void>"(%1)
```
all the content has to be quoted.

https://github.com/llvm/llvm-project/pull/111871