I triggered an internal compiler error today with g++-6:

floc.cc:187:1: internal compiler error: in output_constructor_regular_field, at
varasm.c:4968
 }
 ^
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with preprocessed source if appropriate.
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<builtin>: recipe for target 'floc.o' failed
make: *** [floc.o] Error 1

It seems to stumble about this definition:

struct file_type ftypes[] {
        { .name = "C Source", .extensions = { ".c" } },
        { .name = "C++ Source", .extensions = { ".cc", ".C", ".c++", ".cpp" }
},
        { .name = "C/C++ Header", .extensions = { ".h" } },
};

A Google search indicates that the bug was already reported to gcc and is fixed
upstream. There is was tracked as
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78572

I triggered this with g++-6 in Leap 42.2 and 42.3. Can the upstream fix be
backported to gcc-6?