Tests that the DFG handles x % 1 correctly.

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".


PASS foo(-5.5) is -0.5 on all iterations including after DFG tier-up.
PASS 1 / foo(-1) is -Infinity on all iterations including after DFG tier-up.
PASS successfullyParsed is true

TEST COMPLETE