More logic from complex/test* moved to their own testcases.

src/interfaces/ecpg/test/expected/preproc-define.c

src/interfaces/ecpg/test/expected/preproc-define.stderr

src/interfaces/ecpg/test/expected/preproc-define.stdout

src/interfaces/ecpg/test/expected/preproc-type.c

src/interfaces/ecpg/test/expected/preproc-type.stderr

src/interfaces/ecpg/test/expected/preproc-type.stdout

src/interfaces/ecpg/test/expected/preproc-variable.c

src/interfaces/ecpg/test/expected/preproc-variable.stderr

src/interfaces/ecpg/test/expected/preproc-variable.stdout

src/interfaces/ecpg/test/preproc/Makefile

src/interfaces/ecpg/test/preproc/define.pgc

src/interfaces/ecpg/test/preproc/type.pgc

src/interfaces/ecpg/test/preproc/variable.pgc