[lworld] ValueObject isSubstutiable comparison of float/double should use raw bits

For value objects, the `acmp` bytecode compares two values field by field recursively. When comparing the values of float and double fields the comparison should be returning `true` if the values are the same.
Comparing using the `raw` bits meets this requirement.
This differs from the equals and compare methods that map the `NaN` values to a normalized form, losing information of the difference between different `NaN` values.

The behavior is specified by updates for Valhalla to JVMS Chapter 6 instructions: if_acmpeq and if_acmpne.