[Bug c++/71372] [6/7 Regression] C++ FE drops TREE_THIS_VOLATILE in cp_fold on all tcc_reference trees

[hdusel@tangerine-soft.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71372

--- Comment #16 from Hans-Peter Dusel <hdusel@tangerine-soft.de> ---
Created attachment 38634
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38634&action=edit
Patch for GCC 6.1.0

Patch that applies the changes for official Release of GCC 6.1.0