symtab reader: fix up alternative addresses

CFI symbols need special interpretation and this work is performed by
the add_alternative_address_lookups method.

Some symbol addresses need to be "tweaked" to be correctly interpreted
and this must also happen in add_alternative_address_lookups.

In particular, this commit fixes ARM32 CFI symbol interpretation.

	* src/abg-symtab-reader.cc
	(symtab::add_alternative_address_lookups): Tweak function
	addresses in the same manner as done in symtab::load_.

Signed-off-by: Giuliano Procida <gprocida@google.com>
Change-Id: I45fd4f2e455dc7649361786f2926a8fc9dfc6ac9
1 file changed