the linker was wrongly leaving dynamic relocations for GD-model TLS
defined in the main program when linking the main program as PIE. this
was only suboptimal for dynamic pie, but for static pie it resulted in
runtime failure since there is no dynamic linker to resolve the DTPMOD
reference.
this has been reported as binutils bug #22570.
upstream fix was slightly too late to make it into the release. patch
was not included in mcm for previous binutils versions because it
depends on new upstream infrastructure. now gc-sections should be safe
to use on sh.