'sub' in constant expression is unhandled

[QuLogic]

Running tests (using several patches from #2515) with Go 1.18 fails with:

i64 sub (i64 ptrtoint ([0 x i8]* @"internal/fuzz._ecounters" to i64), i64 ptrtoint ([0 x i8]* @"internal/fuzz._counters" to i64))
panic: unknown constant expr

I think this comes from this bit of code in the fuzzer:

	size := uintptr(unsafe.Pointer(&_ecounters)) - uintptr(addr)

[deadprogram]

@aykevl can you please take a look?

[aykevl]

I'm starting to think it may be better to stub out the entire internal/fuzz package because it makes too many assumptions about the compiler and linker.
(If we ever want to implement fuzz testing in TinyGo, we could revisit this decision).

[deadprogram]

I would agree with that decision for now.