[Bug middle-end/66148] New: [6 regression] build/genpreds: Internal error: abort in choose_enum_order, at genpreds.c:1006

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66148

            Bug ID: 66148
           Summary: [6 regression] build/genpreds: Internal error: abort
                    in choose_enum_order, at genpreds.c:1006
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: danglin at gcc dot gnu.org
  Target Milestone: ---
              Host: hppa64-hp-hpux11.11
            Target: hppa64-hp-hpux11.11
             Build: hppa64-hp-hpux11.11

/test/gnu/gcc/objdir/./prev-gcc/xg++ -B/test/gnu/gcc/objdir/./prev-gcc/
-B/opt/g
nu64/gcc/gcc-5.0/hppa64-hp-hpux11.11/bin/ -nostdinc++
-B/test/gnu/gcc/objdir/pre
v-hppa64-hp-hpux11.11/libstdc++-v3/src/.libs
-B/test/gnu/gcc/objdir/prev-hppa64-
hp-hpux11.11/libstdc++-v3/libsupc++/.libs 
-I/test/gnu/gcc/objdir/prev-hppa64-hp
-hpux11.11/libstdc++-v3/include/hppa64-hp-hpux11.11 
-I/test/gnu/gcc/objdir/prev
-hppa64-hp-hpux11.11/libstdc++-v3/include 
-I/test/gnu/gcc/gcc/libstdc++-v3/libs
upc++ -L/test/gnu/gcc/objdir/prev-hppa64-hp-hpux11.11/libstdc++-v3/src/.libs
-L/test/gnu/gcc/objdir/prev-hppa64-hp-hpux11.11/libstdc++-v3/libsupc++/.libs  
-g -O2 -DIN_GCC    -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W
-Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wmissing-format-attribute
-Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros
-Wno-overlength-strings -Werror   -DHAVE_CONFIG_H -DGENERATOR_FILE
-static-libstdc++ -static-libgcc  -o build/genconditions \
            build/genconditions.o build/rtl.o build/read-rtl.o build/ggc-none.o
build/vec.o build/min-insn-modes.o build/gensupport.o build/print-rtl.o
build/read-md.o build/errors.o .././libiberty/libiberty.a
build/genpreds -c ../../gcc/gcc/common.md ../../gcc/gcc/config/pa/pa.md >
tmp-constrs.h
build/genpreds: Internal error: abort in choose_enum_order, at genpreds.c:1006

First seen in r223163.  r222861 was okay.