Architectures using FMA optimization yield slightly different results so
we cannot assume floating point values will be precisely the same across
different architectures.

The solution in this change is to check "abs(a-b) < tolerance" instead
of comparing the exact values. This will give us confidence that the
histogram buckets are near identical.

Signed-off-by: Seth Bunce <seth.bunce@getcruise.com>

Co-authored-by: Daniel Swarbrick <daniel.swarbrick@gmail.com>
Signed-off-by: Seth Bunce <seth.bunce@getcruise.com>

Per discussion in the pull request, we'd like to avoid having an extra
dependency on a float comparison package. Instead, we copy the float compare
functions from the float comparison package.

The float comparison package we're choosing is this. The author of this
package has commented in the pull request and it looks like we have consensus
that this is the best option.
github.com/beorn7/floats

Signed-off-by: Seth Bunce <seth.bunce@gmail.com>

This change removes the float32 variant of the AlmostEqual funcs, that we will
likely never use. This change also relocates the function into a separate file
to avoid modifying a file that's a fork of another vendored package.

Signed-off-by: Seth Bunce <seth.bunce@gmail.com>