Bug PR29443 - Global variables not emitted to abixml in some cases

Bug PR29443 - Global variables not emitted to abixml in some cases

When a global variable named V has the same name as member variable
that appears in an anonymous scope and if the the abixml writer emits
the member variable V first, it gets confused when comes the time to
emit the global V as it wrongly thinks it's been already emitted.

This is because when emitting the "internal" pretty representation of
the member variable, libabigail fails to consider printing a qualified
name.  So the two 'V' wrongly have names that can't be told apart.

For instance consider the testcase example:

struct A {
  struct {
    int xx; // #0
  };
};

The qualified name of xx, for internal purposes (to name things
internally for the purpose of book keeping) would be:
    'A::__anonymous_struct__::xx'.

Libabigail wrongly names it 'xx', hence the confusion with the global variable.

Fixed thus.

	* src/abg-ir.cc (var_decl::get_pretty_representation): Always use
	qualified name of vars in an anonymous scope for internal
	purposes.
	* tests/data/test-annotate/PR29443-missing-xx.o.annotated.abi: New
	reference test output.
	* tests/test-annotate.cc (in_out_specs): Add the above to the test
	harness.
	* tests/data/test-read-dwarf/PR29443-missing-xx.cc: New source
	code for the test.
	* tests/data/test-read-dwarf/PR29443-missing-xx.o: New test input
	binary.
	* tests/data/test-read-dwarf/PR29443-missing-xx.o.abi: New test
	reference output.
	* tests/data/Makefile.am: Add the new test material to source
	distribution.
	* tests/test-read-dwarf.cc (in_out_specs): Add the above to the
	test harness.

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