[Bug c++/70590] New: [6 Regression] r234810 causes error: location references block not in block tree

["trippels at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70590

            Bug ID: 70590
           Summary: [6 Regression] r234810 causes error: location
                    references block not in block tree
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: trippels at gcc dot gnu.org
                CC: ppalka at gcc dot gnu.org
  Target Milestone: ---

Since r234810 Firefox doesn't build anymore on ppc64le:

trippels@gcc2-power8 xslt % /home/trippels/gcc_test/usr/local/bin/c++ -c -w -O2
-std=gnu++0x txMozillaXMLOutput.ii
/home/trippels/gecko-dev/dom/xslt/xslt/txMozillaXMLOutput.cpp: In member
function âMozExternalRefCountType nsNodeInfoManager::Release()â:
/home/trippels/gecko-dev/dom/xslt/xslt/txMozillaXMLOutput.cpp:1081:1: error:
location references block not in block tree
 }
 ^
&_cycleCollectorGlobal.D.86308
D.356459 = nsCycleCollectingAutoRefCnt::decr (D.356455, this,
&_cycleCollectorGlobal.D.86308, 0B);
/home/trippels/gecko-dev/dom/xslt/xslt/txMozillaXMLOutput.cpp:1081:1: internal
compiler error: verify_gimple failed
0x10b189e3 verify_gimple_in_cfg(function*, bool)
        ../../gcc/gcc/tree-cfg.c:5125
0x109ba45f execute_function_todo
        ../../gcc/gcc/passes.c:1958
0x109bb223 do_per_function
        ../../gcc/gcc/passes.c:1652
0x109bb42f execute_todo
        ../../gcc/gcc/passes.c:2010

Reducing...