tests: llvm-dg-test - remove a useless test and memory leaks
tests: llvm-dg-test - remove a useless test and memory leaks

The TestConstructors has no sense and the basic blocks created
should be again destroyed

Signed-off-by: Marek Chalupa <a05df156a69ad59faa9af9b666ef78009594c145@gmail.com>

mchalupa/dg,mchalupa/dg,mchalupa/dg,mchalupa/dg