The linker of Linux/AArch64 (at least) generates `__bss_start__`,
`__bss_end__`, `_bss_end__`, and `__end__` symbols.
`libmpi_usempi_ignore_tkr.so` is added but `libmpi_usempif08.so`
is not added because `use-mpi-f08` has `contains` statements
in modules and compilers automatically generate compiler-specific
symbols for them. For example, gfortran 4.9 generates
`__mpi_f08_callbacks_MOD_mpi_comm_dup_fn` etc.
Signed-off-by: KAWASHIMA Takahiro <t-kawashima@jp.fujitsu.com>
d468cdb7a6