GCC 4.9.4 + GDC-patch: internal compiler error in libphobos/src/std/math.d:8040:47

[kdevel]

I applied the head

    commit ce249d880969111384d17f744687e427c843f1d4
    Merge: 8a6b7a4 0e517e4
    Author: Eugene Wissner <belka at caraus.de>
    Date:   Tue Apr 10 15:37:32 2018 +0200

        Merge pull request #647 from belka-ew/gdc-49up

        Merge branch gdc-5 into gdc-4.9

of branch gdc-4.9 on top of gcc-4.9.4 and got this error:

/bin/sh ../libtool --tag=D   --mode=compile 
/scratch/mockbuild1/bld-4.9.4/gcc-objdir/./gcc/gdc 
-B/scratch/mockbuild1/bld-4.9.4/gcc-objdir/./gcc/ 
-B/scratch/gcc-4.9.4/x86_64-unknown-linux-gnu/bin/ 
-B/scratch/gcc-4.9.4/x86_64-unknown-linux-gnu/lib/ -isystem 
/scratch/gcc-4.9.4/x86_64-unknown-linux-gnu/include -isystem 
/scratch/gcc-4.9.4/x86_64-unknown-linux-gnu/sys-include     -O2 
-g  -nostdinc -pipe -Wno-deprecated -I 
/scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/libphobos/src -I 
/scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/libphobos/libdruntime -I 
../libdruntime -I . -c -o std/net/curl.lo 
/scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/libphobos/src/std/net/curl.d
libtool: compile:  
/scratch/mockbuild1/bld-4.9.4/gcc-objdir/./gcc/gdc 
-B/scratch/mockbuild1/bld-4.9.4/gcc-objdir/./gcc/ 
-B/scratch/gcc-4.9.4/x86_64-unknown-linux-gnu/bin/ 
-B/scratch/gcc-4.9.4/x86_64-unknown-linux-gnu/lib/ -isystem 
/scratch/gcc-4.9.4/x86_64-unknown-linux-gnu/include -isystem 
/scratch/gcc-4.9.4/x86_64-unknown-linux-gnu/sys-include -O2 -g 
-nostdinc -pipe -Wno-deprecated -I 
/scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/libphobos/src -I 
/scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/libphobos/libdruntime -I 
../libdruntime -I . -c 
/scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/libphobos/src/std/net/curl.d  -fPIC -fversion=Shared -o std/net/.libs/curl.o
/scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/libphobos/src/std/math.d:8040:47: internal compiler error: Speicherzugriffsfehler
              return cast(Unqual!T) (T(1) << bsr(val) + type);
                                                ^
0x9e3b0f crash_signal
    /scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/gcc/toplev.c:337
0xeb7af0 htab_hash_string
    /scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/libiberty/hashtab.c:839
0x7bc0f7 external_ref_hasher::hash(external_ref const*)
    /scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/gcc/dwarf2out.c:7510
0x7bc0f7 hash_table<external_ref_hasher, 
xcallocator>::find_slot(external_ref const*, insert_option)
    /scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/gcc/hash-table.h:505
0x7bc0f7 lookup_external_ref
    /scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/gcc/dwarf2out.c:7538
0x7bc19d optimize_external_refs_1
    /scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/gcc/dwarf2out.c:7576
0x7bc1c8 optimize_external_refs_1
    /scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/gcc/dwarf2out.c:7580
0x7bc5ed optimize_external_refs
    /scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/gcc/dwarf2out.c:7630
0x7bc9a5 output_comp_unit
    /scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/gcc/dwarf2out.c:8816
0x7d7319 dwarf2out_finish
    /scratch/mockbuild1/bld-4.9.4/gcc-4.9.4/gcc/dwarf2out.c:24301
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.

Is GCC 4.9 still maintained?