Missing local variable definitions

[rbran]

Implement the API to identify local variable definitions.

[rbran]

The commit 8247ffc implement the register and stack variable names, although the registers seems to work fine, the variable in stack depends on the TIL UDF (struct) deserializer, it seems to be incorrectly calculating the members offset some times.

It's also unable to identify local variables in versions older then ~v7.6