[Sanitizers] Fix fake_test_gc not working on devices (#91284)

The way the LIT RUN command is currently constructed ( %run not --crash
%t ) causes the test failure on devices - since 'not' is a LLVM built
command, not available on devices.

Changing the command to read 'not --crash %run %t' fixes it, as 'not'
now executes on the host running the test.

rdar://115914588



Co-authored-by: Mariusz Borsa <m_borsa@apple.com>