Riscv shared libraries should not export __global_pointer$.

Riscv shared libraries should not export __global_pointer$.

	ld/
	* emulparams/elf32lriscv-defs.sh (SDATA_START_SYMBOLS): Mark
	__global_pointer$ as HIDDEN.
	* testsuite/ld-riscv-elf/gp-hidden-64.rd: New.
	* testsuite/ld-riscv-elf/gp-hidden-lib.rd: New.
	* testsuite/ld-riscv-elf/gp-hidden-lib.s: New.
	* testsuite/ld-riscv-elf/gp-hidden-ver-64.rd: New.
	* testsuite/ld-riscv-elf/gp-hidden-ver.rd: New.
	* testsuite/ld-riscv-elf/gp-hidden-ver.s: New.
	* testsuite/ld-riscv-elf/gp-hidder-ver.ver: New.
	* testsuite/ld-riscv-elf/gp-hidden.rd: New.
	* testsuite/ld-riscv-elf/gp-hidden.s: New.
	* testsuite/ld-riscv-elf/gp-hidden.sd: New.
	* testsuite/ld-riscv-elf/ld-riscv-elf.exp: Change riscv to riscv*.
	Run the new tests with run_ld_link_tests.