[PATCH] lib, ruby: make use of -Wl,--no-undefined configurable

[Jinwoo Lee]

> That probably will not change; IIRC bash 3.2.57 is released under GPLv2
> and bash >= 4 GPLv3. You just need to install separate bash (brew, ports,
> wherever) in order to run these tests in OS X.

I installed bash from MacPorts and ran `make test' again, but the result
is not so good.  The error message is just "make: *** [test] Error 9",
and I can't tell what exactly has failed.

Here's the log:

$ make test
cd bindings/ruby && \
		EXTRA_LDFLAGS="" \
		LIBNOTMUCH="../../lib/libnotmuch.dylib" \
		ruby extconf.rb --vendor
creating Makefile
/Applications/Xcode.app/Contents/Developer/usr/bin/make -C bindings/ruby
linking shared-object notmuch.bundle
ld: warning: directory not found for option '-L/usr/local/lib'
ld: warning: directory not found for option '-L/usr/local/lib'
ld: warning: ignoring file ../../lib/libnotmuch.dylib, file was built for x86_64 which is not the architecture being linked (i386): ../../lib/libnotmuch.dylib
Use "/Applications/Xcode.app/Contents/Developer/usr/bin/make V=1" to see the verbose compile lines.
CC  -g -O2 test/arg-test.o
CC test/arg-test
CC  -g -O2 test/hex-xcode.o
CC test/hex-xcode
CC  -g -O2 test/random-corpus.o
CC  -g -O2 test/database-test.o
CXX test/random-corpus
CC  -g -O2 test/parse-time.o
CC test/parse-time
CC  -g -O2 test/smtp-dummy.o
CC test/smtp-dummy
CXX  -g -O2 test/symbol-test.o
test/symbol-test.cc:7:14: warning: unused parameter 'argc' [-Wunused-parameter]
int main(int argc, char** argv) {
             ^
1 warning generated.
CXX test/symbol-test
CXX  -g -O2 test/make-db-version.o
CXX test/make-db-version
INFO: using 2 minute timeout for tests

T000-basic: Testing the test framework itself.
make: *** [test] Error 9