Re: PR26978, Inconsistency for strong foo@v1 and weak foo@@v1

Re: PR26978, Inconsistency for strong foo@v1 and weak foo@@v1

Commit 726d7d1ecf opened a hole that allowed a u.i.link loop to be
created, resulting in _bfd_generic_link_add_one_symbol never
returning.  Fix that.  Note that the MIND case handles two types of
redefinition.  For a new indirect symbol we'll have string non-NULL.
For a new def, string will be NULL.  So moving the string comparison
earlier would work.  However, we've already looked up inh in the first
case so can dispense with name comparisons.  Either way, for a new def
we'll get to the defweak test and possibly cycle.  Which is what we
want here.

	PR 31615
	PR 26978
	* linker.c (_bfd_generic_link_add_one_symbol <MIND>): Test for
	exactly matching indirect symbols before cycling on a defweak.