This exports a utility function, dwarf2_reg_to_regnum_or_error, that
was previously private to dwarf2loc.c.

gdb/ChangeLog
2014-12-12  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* dwarf2loc.h (dwarf2_reg_to_regnum_or_error): Declare.
	* dwarf2loc.c (dwarf2_reg_to_regnum_or_error): Rename from
	translate_register.  Now public.
	(dwarf2_compile_expr_to_ax): Update.