gold/
* output.cc (Output_section::add_merge_input_section): Allow
to merge sections if the alignment is more than character size.
* merge.h (Output_merge_string::Output_merge_string): Remove
assert.
* merge.cc (Output_merge_string<Char_type>::do_add_input_section): Count
only not-null strings. Check the alignment of strings.
* stringpool.h
(Stringpool_template<Stringpool_char>::Stringpool_template): Add
alignment as the argument.
(Stringpool_template<Stringpool_char>::addralign_): New class member.
* stringpool.cc (Stringpool_template<Stringpool_char>::new_key_offset):
Align non-zero length strings according to the addralign_.
(Stringpool_template<Stringpool_char>::set_string_offsets):
Updating offsets according to the given alignment.
* testsuite/Makefile.am (text_section_grouping): Test if string
literals are getting merged.
* testsuite/Makefile.in: Regenerate.
* testsuite/merge_string_literals_1.c: New file.
* testsuite/merge_string_literals_2.c: Ditto.
* testsuite/merge_string_literals.sh: Ditto.
