Bug 29692 - Support binaries with empty symbol table

Bug 29692 - Support binaries with empty symbol table

Some binaries can have a symbol table in which no symbol is actually
defined and exported.  That binary would thus have an empty ABI
corpus.

Interestingly, Libabigail's DWARF reader is emits an error when
it encounters such binaries.

This patch adds the support for those binaries.

	* src/abg-dwarf-reader.cc (reader::read_debug_info_into_corpus):
	Get out early also upon having an empty symbol table.
	* src/abg-elf-reader.cc (reader::read_corpus): Error out only if
	there is no symbol table for the binary.  If an empty symbol table
	is found however, that is not an error.
	* tests/data/test-read-dwarf/PR29692-kdelibs3-libkjava.so.1.0.0:
	New binary test input.
	* tests/data/test-read-dwarf/PR29692-kdelibs3-libkjava.so.1.0.0.abi:
	New expected abixml file.
	* tests/data/Makefile.am: Add the new input test files to source
	distribution.
	* tests/test-read-dwarf.cc (in_out_specs): Add the new test inputs
	above to this test harness.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>