[Bug fortran/87753] READ statement with nested implied do broken with optimization

[hvandam at bnl dot gov]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87753

--- Comment #1 from Hubertus van Dam <hvandam at bnl dot gov> ---
Created attachment 44900
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44900&action=edit
The data file that the program reads