gdb-7.12.1 for arm-rtems4.12 fails to build on FreeBSD 11.0

Hi,

I am getting the following build failure on FreeBSD 11.0:

In file included from ../../gdb-7.12.1/gdb/arch/arm.c:20:
In file included from ../../gdb-7.12.1/gdb/common/common-defs.h:31:
In file included from build-gnulib/import/stdio.h:53:
build-gnulib/import/stddef.h:104:3: error: typedef redefinition with 
different types ('union max_align_t' vs 'long double')
} max_align_t;
   ^
/usr/include/c++/v1/stddef.h:57:21: note: previous definition is here
typedef long double max_align_t;
                     ^
It seems build-gnulib/import/stddef.h is created assuming there is no 
host provided version. I cannot figure out how the configure phase test 
works and why this is happening.

Any hints?

Thanks
Chris