LTO: Properly handle wrapper symbols in IR

LTO: Properly handle wrapper symbols in IR

When a wrapper symbol, __wrap_FOO, is defined in IR, its resolution
should be LDPR_PREVAILING_DEF, not PREVAILING_DEF_IRONLY, since LTO
doesn't know that __wrap_FOO provides definition of FOO.  And resolution
of FOO should be LDPR_RESOLVED_IR since it is resolved by __wrap_FOO in
IR.

	PR ld/24406
	* ld.texi: Remove LTO warning from --wrap.
	* plugin.c (get_symbols): Update resolution for wrapper and
	wrapped symbols.
	* testsuite/ld-plugin/lto.exp: Run ld/24406 tests.
	* testsuite/ld-plugin/pr24406-1.c: New file.
	* testsuite/ld-plugin/pr24406-2a.c: Likewise.
	* testsuite/ld-plugin/pr24406-2b.c: Likewise.