With revision 160368 the tree built.
From revision 160380 and on including at least 160431, build has failed as follows:

libtool: compile:  /tmp/hpautotest-gcc1/cris-elf/gccobj/./gcc/xgcc -shared-libgcc -B/tmp/hpautotest-gcc1/cris-elf/gccobj/./gcc -nostdinc++ -L/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/libstdc++-v3/src -L/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/libstdc++-v3/src/.libs -nostdinc -B/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/newlib/ -isystem /tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/newlib/targ-include -isystem /tmp/hpautotest-gcc1/gcc/newlib/libc/include -B/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/libgloss/cris -L/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/libgloss/libnosys -L/tmp/hpautotest-gcc1/gcc/libgloss/cris -B/tmp/hpautotest-gcc1/cris-elf/pre/cris-elf/bin/ -B/tmp/hpautotest-gcc1/cris-elf/pre/cris-elf/lib/ -isystem /tmp/hpautotest-gcc1/cris-elf/pre/cris-elf/include -isystem /tmp/hpautotest-gcc1/cris-elf/pre/cris-elf/sys-include -I/tmp/hpautotest-gcc1/gcc/libstdc++-v3/../gcc -I/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/libstdc++-v3/include/cris-elf -I/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/libstdc++-v3/include -I/tmp/hpautotest-gcc1/gcc/libstdc++-v3/libsupc++ -fno-implicit-templates -Wall -Wextra -Wwrite-strings -Wcast-qual -fdiagnostics-show-location=once -ffunction-sections -fdata-sections -g -O2 -c /tmp/hpautotest-gcc1/gcc/libstdc++-v3/libsupc++/eh_alloc.cc -o eh_alloc.o
/tmp/hpautotest-gcc1/gcc/libstdc++-v3/libsupc++/eh_alloc.cc: In function 'void* __cxxabiv1::__cxa_allocate_exception(std::size_t)':
/tmp/hpautotest-gcc1/gcc/libstdc++-v3/libsupc++/eh_alloc.cc:97:1: internal compiler error: in set_mem_attributes_minus_bitpos, at emit-rtl.c:1674

will attach eh_alloc.ii momentarily.

Authors of patches in suspect revision range CC:ed.