Added option for static linking gcc sanitizers.

If you like to preload a sanitized library in front of an application, it will
fail, because it is not the first in the library list anymore. This behaviour
is gcc specific - clang will static link the sanitizers instead. To get the
same for gcc, the new SANITIZE_LINK_STATIC flag will link the sanitizers
static in gcc environments.

Note: The preloaded executable must be sanitized, too! Otherwise ASan will
      print an error message!

cmake/FindSanitizers.cmake

@@ -22,6 +22,13 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 # SOFTWARE.
 
+# If any of the used compiler is a GNU compiler, add a second option to static
+# link against the sanitizers.
+option(SANITIZE_LINK_STATIC "Try to link static against sanitizers." Off)
+
+
+
+
 set(FIND_QUIETLY_FLAG "")
 if (DEFINED Sanitizers_FIND_QUIETLY)
     set(FIND_QUIETLY_FLAG "QUIET")