Prevent compile-phonemes use of phontab, en_dict

[jbowler]

espeak-ng --compile-phonemes generates phontab, but during the
generation it starts by reading the old phontab. If works just fine,
apart from an error message, if this doesn't exist but if it does exist
it is not clear whether it might end up using old or bad data (e.g.
possibly crashing if phontab is corrupted making it very non-obvious how
to fix the problem...)

The same applies to en_dict as a result of espeak-ng defaulting to the
voice 'en'; again the phontab build works if en_dict is absent but a
spurious message is output. It's not clear what would happen if someone
tried to build a reduced espeak-ng configuration with just one (non
'en') language.

The fix is to change espeak_ng_CompilePhonemeDataPath to call LoadVoice
with a new flag to indicate the voice structure is just required to
compile phoneme data (I changed the error message as well to make it
clear where it comes from - there are two identical error messages, the
other one is in voices.c)

Within LoadVoice the flag causes LoadVoice to not set a default language
or voicename and to skip loading the old phontab or dictionary (both of
which fail in a git clean -dfx build).

I checked the result by doing a compile from-scratch build sequence with
and without the patch, i.e. I did:

git clean -dfx
./autogen.sh
./configure --prefix=a-test-directory
make
make install

Then I compared the two copies of "a-test-directory" as well as the log
file output:

$ diff -r logs/*
diff -r logs/original/make.log logs/patched/make.log
175,176d174
< Unknown phoneme table: 'en'
< Can't read dictionary file:
'/home/jbowler/src/espeak-ng/master/espeak-ng-data/en_dict'

$ diff --no-dereference -r local.original local.patched
Binary files local.original/bin/speak-ng and local.patched/bin/speak-ng differ
Binary files local.original/lib/libespeak-ng.a and local.patched/lib/libespeak-ng.a differ
Binary files local.original/lib/libespeak-ng.so.1.1.51 and local.patched/lib/libespeak-ng.so.1.1.51 differ

So the change has not altered phontab or any of the other generated
files, only the binaries as would be expected. (Note that I am
comparing truely clean builds; what you get if you download the source
and build from scratch. This is the standard approach for people who
build for distribution.)

Signed-off-by: John Bowler jbowler@acm.org

[jbowler]

This is the fix for PR #928. A similar bug exists in the dictionary creation with a clean build. By "clean" I mean freshly cloned or git clean -dfx, not make clean or even make distclean, which doesn't work properly. I can't fix that bug in the same way, but I can submit a patch to work round it in Makefile.am

[jbowler]

Ok... git has merged the change for the dictionary creation issue into this pull request, but the two commits are entirely independent.

[valdisvi]

Thanks for contribution! Your pull request is merged into project.