riscv: fix relocs for global syms
riscv: fix relocs for global syms

loads and stores to global symbols need to go via the
GOT (at least for weaks), otherwise -run doesn't work.
Ideally we'd generate GOT relocs (and loads) always and replace
them with PCREL relocs and adds during linking.

mirror/tinycc,mingodad/tinycc,mingodad/tinycc,mingodad/tinycc,mirror/tinycc,mingodad/tinycc,mirror/tinycc,mirror/tinycc