Make translations of strings with <inttypes.h> macros work with musl libc.
* gettext-tools/src/write-mo.h (no_redundancy): New declaration.
* gettext-tools/src/write-mo.c (SIZEOF): New macro.
(no_redundancy): New variable.
(struct sysdep_instantiation_rule): New type.
(useful_instantiation_rules): New variable.
(concat_prefix_cs, get_sysdep_segment_value): New functions.
(write_table): Add a second pass, that instantiates system dependent string
pairs.
* gettext-tools/src/msgfmt.c (long_options): Add --no-redundancy.
(main): Handle the --no-redundancy option.
(usage): Document the --no-redundancy option.
* gettext-tools/doc/msgfmt.texi: Document the --no-redundancy option.
* gettext-tools/tests/msgfmt-12: Test the msgfmt result with and without
--no-redundancy.
* gettext-tools/tests/msgunfmt-2: Pass option --no-redundancy to msgfmt.
* NEWS: Mention the change.
* gettext-tools/tests/format-c-3: Include the redundant instantiations in the
expected result of msgunfmt.
* gettext-tools/tests/format-c-4: Likewise.
