Emit[All/Any][True/False] now takes respect of the current mask
fixed masking of the Then-Successor for SierraIf
fixed return for BO_LAnd and BO_LOr
fixed return for the Sierra Logical Not
make `EmitBranchOnBoolExpr' return the result
fixed the check that triggers Sierra CodeGen for conditionals: now only check
the type of the conditional's condition
fixed code generation for vectorial fall-through case: we dont need to mask,
      just return the result value
added case for ImplicitCast expr to just skip them (needs more testing, maybe we
    have to request that the SubExpr is a vectorial conditional)
fixed code generation for vectorial conditionals in JumpStmts