[Bug demangler/88629] Heap-buffer-overflow problem in function d_expression_1 in cp-demangle.c, as demonstrated by c++filt

[wcventure at 126 dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88629

--- Comment #2 from Cheng Wen <wcventure at 126 dot com> ---
Created attachment 45296
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=45296&action=edit
POC3