Improves the coding style in SValBuilder. This patch:

- renames evalCastNL and evalCastL to evalCastFromNonLoc and
  evalCastFromLoc (avoid abbreviations that aren't well known).

- makes all function parameter names start with a lower case letter
  for consistency and distinction from member variables.

- avoids abbreviations in function parameter names.

Reviewed by kremenek@apple.com.

llvm-svn: 126722