Some validity gymnastics!

rtree-c/src/ReduceC.hs

rtree-c/test/cases/small/structfn.c

rtree-c/test/expected/add/reduction/r000000000.c

rtree-c/test/expected/add/reduction/r000000001.c

rtree-c/test/expected/add/reduction/r000000010.c

rtree-c/test/expected/add/reduction/r000000011.c

rtree-c/test/expected/add/reduction/r0000001.c

rtree-c/test/expected/add/reduction/r00000100.c

rtree-c/test/expected/add/reduction/r000001000.c

rtree-c/test/expected/add/reduction/r000001001.c

rtree-c/test/expected/add/reduction/r00000101.c

rtree-c/test/expected/add/reduction/r000001010.c

rtree-c/test/expected/add/reduction/r000001011.c

rtree-c/test/expected/add/reduction/r0000011.c

rtree-c/test/expected/add/reduction/r00000110.c

rtree-c/test/expected/add/reduction/r00000111.c

rtree-c/test/expected/add/reduction/r00001000.c

rtree-c/test/expected/add/reduction/r00001001.c

rtree-c/test/expected/add/reduction/r00001010.c

rtree-c/test/expected/add/reduction/r00001011.c