exa2pro/starpu-max: porting work to Maxeler DFE @ 7e36b7364ec1ce3572d8c3f0339a7cd66db75854

Nathalie Furmento be06e1d5de check in configure.ac if unsetenv is available		13 lat temu
..
invalid_blocking_calls.c	685f84fcdb Include valgrind.h in helper.h, not directly in the tests.	13 lat temu
invalid_tasks.c	9aaa7caf99 tests: if starpu_init() returns -ENODEV, skip the test, do not fail it	13 lat temu
starpu_init_noworker.c	be06e1d5de check in configure.ac if unsetenv is available	13 lat temu