move add{Load,Store}Data out of ApfV4GeneratedBase class into ApfV4Generator class

these instructions are not useful in this form on APFv6,
and the ApfV6Generator class is now only capable of building
code for an APFv6 capable interpreter (as it immediately switches
into APFv6 mode in the first instruction)

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I8c6ef4b94a79017dbeeb4c56269de6612a31a26b
2 files changed