Bug#950594: flang FTBFS: dwz: Too many DIEs, not optimizing

[Adrian Bunk]

Source: flang
Version: 20190329-4
Severity: serious
Tags: ftbfs

...
   dh_dwz -O--buildsystem=cmake -O--builddirectory=/tmp/flang-20190329/debian/build
        install -d debian/flang-7/usr/lib/debug/.dwz/x86_64-linux-gnu
        dwz -mdebian/flang-7/usr/lib/debug/.dwz/x86_64-linux-gnu/flang-7.debug -M/usr/lib/debug/.dwz/x86_64-linux-gnu/flang-7.debug -- debian/flang-7/usr/bin/flang-7 debian/flang-7/usr/bin/flang1 debian/flang-7/usr/bin/flang2
dwz: debian/flang-7/usr/bin/flang-7: Too many DIEs, not optimizing
dwz: debian/flang-7/usr/bin/flang1: DWARF compression not beneficial - old size 2259002 new size 2265054
dh_dwz: error: dwz -mdebian/flang-7/usr/lib/debug/.dwz/x86_64-linux-gnu/flang-7.debug -M/usr/lib/debug/.dwz/x86_64-linux-gnu/flang-7.debug -- debian/flang-7/usr/bin/flang-7 debian/flang-7/usr/bin/flang1 debian/flang-7/usr/bin/flang2 returned exit code 1
make: *** [debian/rules:14: binary] Error 25