valgrind-tests and suppression files

[Marc Nieper-Wißkirchen]

Is there any built-in support in the valgrind-tests module for
suppression files? For example, if I want to run my tests under
valgrind (if available), I write

LOG_COMPILER = $(VALGRIND)

or, in case I use libtool,

LOG_COMPILER = $(LIBTOOL) --mode=execute $(VALGRIND)

But how to add valgrind suppression files in this context?

LOG_COMPILER = $(VALGRIND) --suppressions=...

is not a good solution because it will fail when VALGRIND is empty
because valgrind-tests couldn't find a valgrind.

What's the canonical solution of this problem?