abidiff: Remove member function diff blank lines.

Currently, lists of member function deletions, additions and changes
are each followed by a blank line in abidiff output.

While this formatting works reasonably well in leaf-changes-only mode
for top-level changes to types, it is inconsistent with everthing
else. In particular, when reporting member function diffs in default
mode, or more deeply nested in leaf mode, the blank lines are
jarring.

There was also no test coverage for leaf-changes-only mode.

This change removes these blank lines and associated state variables
and logic. It adds a test case for leaf-changes-only mode.

Note that the patch also modifies default mode reporting of member
types, template member functions and template member classes
analogously, but I wasn't able to exercise those code paths.

	* src/abg-default-reporter.cc (report): In the
	class_or_union_diff overload, don't emit a new line after each
	list of member function, member type, template member
	function and template member class changes.
	* src/abg-leaf-reporter.cc (report): : In the
	class_or_union_diff overload, don't emit a new line after each
	list of member function changes.
	* tests/data/Makefile.am: Add new test case files.
	* tests/data/test-abidiff-exit/test-leaf-cxx-members-v0.cc:
	New test case for --leaf-changes-only member function diffs.
	* tests/data/test-abidiff-exit/test-leaf-cxx-members-v0.o:
	Ditto.
	* tests/data/test-abidiff-exit/test-leaf-cxx-members-v1.cc:
	Ditto. Also add a TODO regarding a potentially bad diff.
	* tests/data/test-abidiff-exit/test-leaf-cxx-members-v1.o:
	Ditto.
	* tests/data/test-abidiff/test-struct1-report.txt: Remove
	blank lines after member function changes lists.
	* tests/data/test-diff-dwarf/test41-PR20476-hidden-report-0.txt:
	Ditto.
	* tests/data/test-diff-pkg/tbb-4.1-9.20130314.fc22.x86_64--tbb-4.3-3.20141204.fc23.x86_64-report-0.txt:
	Ditto.
	* tests/test-abidiff-exit.cc: Add new test case.

Reviewed-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Giuliano Procida <gprocida@google.com>
Signed-off-by: Dodji Seketeli <dodji@redhat.com>
12 files changed