Replace __attribute__((visibility("protected")))

Replace __attribute__((visibility("protected")))

With copy relocation, address of protected data defined in the shared
library may be external.  Compiler shouldn't asssume protected data will
be local.  But due to

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65248

__attribute__((visibility("protected"))) doesn't work correctly, we need
to use asm (".protected xxx") instead.

Cherry-pick from master: e0ed2fb40a0e29c43cf60addc74741dab15f2e05
	* elf/ifuncdep2.c (global): Replace
	__attribute__((visibility("protected"))) with
	asm (".protected global").
	* elf/ifuncmod1.c (global): Likewise.
	* elf/ifuncmod5.c (global): Likewise.