Co-authored-by: Nick Fitzgerald <fitzgen@gmail.com>

in non-trapping mode

Co-authored-by: Nick Fitzgerald <fitzgen@gmail.com>

It was occasionally running into an 'attempt to multiply with overflow'
for 32-bit memories, so we check the value before casting to avoid that.

for using eq, but it is the only value that is not equal to itself,
so ne will work.

an f64. This is necessary because `i64::MAX as f64` will result in an
f64 value that is not representable by an i64.

…ctions

that must check if the memory offset plus the size of the type is within the bounds
of our memory. In order for us to emit this code, that value must fit in a u64.
In the case where the memory offset is u64::MAX, then our rust code panics in trying
to generate the wasm due to an attempt to add with overflow. To solve this, I've added
an upper bound on our memory offsets for load operations while running in non-trapping
mode.

… mode

This was happening with modules that had a large number of memory.grow
or table.grow instructions.