OpenBLAS: Compiler Failure on POWER8 with /kernel/power/i{c,d,s,z}a{min,max}.c

I updated my installations on my POWER8 machine and since version 0.3.6 up to the current development branch, the build process fails with:

$ make  MAKE_NB_JOBS=1
...
cc -c -Ofast -mcpu=power8 -mtune=power8 -mvsx -malign-power -DUSE_OPENMP -fno-fast-math -fopenmp -DMAX_STACK_ALLOC=2048 -fopenmp -Wall -m64 -DF_INTERFACE_GFORT -fPIC -DSMP_SERVER -DUSE_OPENMP -DNO_WARMUP -DMAX_CPU_NUMBER=160 -DMAX_PARALLEL_NUMBER=1 -DVERSION=\"0.3.8.dev\" -DASMNAME=isamax_k -DASMFNAME=isamax_k_ -DNAME=isamax_k_ -DCNAME=isamax_k -DCHAR_NAME=\"isamax_k_\" -DCHAR_CNAME=\"isamax_k\" -DNO_AFFINITY -I.. -UDOUBLE  -UCOMPLEX -UCOMPLEX -UDOUBLE -DUSE_ABS  -UUSE_MIN ../kernel/power/isamax.c -o isamax_k.o
../kernel/power/isamax.c: In function ‘siamax_kernel_64’:
../kernel/power/isamax.c:288:1: internal compiler error: in build_int_cst_wide, at tree.c:1210
 }
 ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://bugzilla.redhat.com/bugzilla> for instructions.
Preprocessed source stored into /tmp/ccriHyPV.out file, please attach this to your bugreport.
make[1]: *** [isamax_k.o] Error 1
make[1]: Leaving directory `/root/OpenBLAS/kernel'
make: *** [libs] Error 1

OS Details: CentOS 7.6 ppc64el, gcc 4.8.5, gfortran 4.8.5, IBM POWER8 LC822