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libdwfl fails to report some modules in corefiles containing non-contiguous and interleaving shared library segments.

For example

          [...]
          7f0972082000-7f09720a4000 00000000 139264      /usr/lib64/ld-2.17.so
          7f09720a4000-7f09720a5000 00000000 4096        /memfd:mozilla-ipc (deleted)
          7f09720a5000-7f09720a7000 00000000 8192        /memfd:mozilla-ipc (deleted)
          7f09720a7000-7f09720a9000 00000000 8192        /memfd:mozilla-ipc (deleted)
          7f0972134000-7f0972136000 00000000 8192        /usr/lib64/firefox/libmozwayland.so
          7f0972136000-7f0972137000 00002000 4096        /usr/lib64/firefox/libmozwayland.so
          7f0972137000-7f0972138000 00003000 4096        /usr/lib64/firefox/libmozwayland.so
          7f0972138000-7f0972139000 00003000 4096        /usr/lib64/firefox/libmozwayland.so
          7f097213a000-7f0972147000 00000000 53248       /usr/lib64/firefox/libmozsqlite3.so
          7f0972147000-7f097221e000 0000d000 880640      /usr/lib64/firefox/libmozsqlite3.so
          7f097221e000-7f0972248000 000e4000 172032      /usr/lib64/firefox/libmozsqlite3.so
          7f0972248000-7f0972249000 0010e000 4096        /usr/lib64/firefox/libmozsqlite3.so
          7f0972249000-7f097224c000 0010e000 12288       /usr/lib64/firefox/libmozsqlite3.so
          7f097224c000-7f0972250000 00111000 16384       /usr/lib64/firefox/libmozsqlite3.so
          7f0972250000-7f0972253000 00000000 12288       /usr/lib64/firefox/liblgpllibs.so
          [...]
          7f09722a3000-7f09722a4000 00021000 4096        /usr/lib64/ld-2.17.so
          7f09722a4000-7f09722a5000 00022000 4096        /usr/lib64/ld-2.17.so

In between non-contiguous ld-2.17.so segments there are a number of segments for other shared libraries. dwfl_segment_report_module can either fail to report the modules corresponding to these libraries or prematurely close the module's file descriptors.