gdbserver: make some functions static in linux-x86-low.c

gdbserver: make some functions static in linux-x86-low.c

These functions are only used in this file, so should be static.

gdb/gdbserver/ChangeLog:

	* linux-x86-low.c (x86_linux_regs_info, amd64_emit_eq_goto,
	amd64_emit_ne_goto, amd64_emit_lt_goto, amd64_emit_le_goto,
	amd64_emit_gt_goto, amd64_emit_ge_goto, amd64_emit_ge_goto,
	i386_emit_eq_goto, i386_emit_ne_goto, i386_emit_lt_goto,
	i386_emit_le_goto, i386_emit_gt_goto, i386_emit_ge_goto): Make
	static.

Change-Id: I703da41867735aefadd49140e80cd60f6ab9ad39