Bug#759696: 3dldf: FTBFS on non-*amd64: invalid free in arc_1 test

["Aaron M. Ucko" <ucko@debian.org>]

Source: 3dldf
Version: 2.0.3+dfsg-1
Severity: serious
Justification: fails to build from source

Builds of 3dldf for all architectures but (linux-)amd64 and
kfreebsd-amd64 have been failing with errors along the lines of

  make[4]: Entering directory '/«BUILDDIR»/3dldf-2.0.3+dfsg/examples'
  ../src/3dldf arc_1.ldf
  *** Error in `../src/3dldf': free(): invalid pointer: 0x093c8840 ***
  make[4]: *** [arc_1.mp] Aborted
  Makefile_sub:21: recipe for target 'arc_1.mp' failed

Could you please take a look?  FWIW, I've generally had good results
with GCC's new -fsanitize=address flag.

Thanks!