Really fix riscv shared library __global_pointer$ problem.
ld/
* emulparams/elf32lriscv-defs.sh (SDATA_START_SYMBOLS): Remove HIDDEN.
Don't define __global_pointer$ when CREATE_SHLIB.
* testsuite/ld-riscv-elf/gp-hidden-64.rd,
* testsuite/ld-riscv-elf/gp-hidden-lib.rd,
* testsuite/ld-riscv-elf/gp-hidden-lib.s,
* testsuite/ld-riscv-elf/gp-hidden-ver-64.rd,
* testsuite/ld-riscv-elf/gp-hidden-ver.rd,
* testsuite/ld-riscv-elf/gp-hidden-ver.s,
* testsuite/ld-riscv-elf/gp-hidden-ver.ver,
* testsuite/ld-riscv-elf/gp-hidden.rd,
* testsuite/ld-riscv-elf/gp-hidden.s,
* testsuite/ld-riscv-elf/gp-hidden.sd: Delete.
* testsuite/ld-riscv-elf/gp-test-lib.sd,
* testsuite/ld-riscv-elf/gp-test.s,
* testsuite/ld-riscv-elf/gp-test.sd: New.
* testsuite/ld-riscv-elf/ld-riscv-elf.exp: Rewrite gp tests.