SPU Analyzer: Fix support for multi-block value merge

[elad335]

• Allow detection of values modified in an inner loop for PUTLLC16 pattern detection with the use of value origins and invalidation while stepping through the code. Also fix some missed detections by comparing source register instead of the value itself at PUTLLC time, this is to allow selection of two potential write destinations at runtime inside the atomic loop such as by if statement.
• Fix LSA state analysis. (do not override it in GETLLAR, instead save a masked value individually)