[Bug c++/87481] New: Endless loop with optimisation in C++17

[bug-reporter at tuta dot io]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87481

            Bug ID: 87481
           Summary: Endless loop with optimisation in C++17
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: bug-reporter at tuta dot io
  Target Milestone: ---

Created attachment 44773
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44773&action=edit
minimal example

Compile the attached code with 'std=c++17 -O1'.

This will generate the message "minimal.cc:9:45: error: ‘millliseconds’ is not
a member of ‘std::chrono’" and then leave the compiler an endless,
memory-eating loop. I can reproduce the bug with any version of g++ that
supports C++17 and any optimisation level greater than zero.