Use correct size_t when determining if a value fits in a byte (#42987)

Use correct size_t when determining if a value fits in a byte (#42987)

- Use target_size_t when determining if a value fits in a byte when value is represented in the function as a ssize_t or cnssval_ssize_t. This drops the upper 32bits of a possibly 64bit size_t when performing the comparison on TARGET_X86 platforms. Those bits are uninitialized if the value not a reloc.