Under some test case layouts the call relocation
panicking with an underflow. Use `wrapping_sub` to
signal that this is expected.
The fuzzer took a while to generate such a test case.
And I can't introduce it as a regression test because
when running via the regular clif-util run tests the
layout is different and the test case passes!
I think this is because in the fuzzer we only add
one trampoline, while in clif-util we build trampolines
for each funcion in the file.
Co-authored-by: Jamey Sharp <jsharp@fastly.com>
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