Fix the "@gprel relocation against dynamic symbol xxx" linker error.
Variables defined in the link unit and small enough to be put in the
short data section will have a gp-relative access sequence (using the
@gprel relocation). It is invalid to have @gprel relocations in shared
libraries, because they are to be resolved by the static linker and
not the dynamic linker. The -fpic option will cause @ltoff relocations
for @gprel relocations, but the side-effects are untested (if any).
Instead, disable/eliminate the short data section to achieve the same.
8f6a0ee959