add new Literal API for pure literal expressions:

Design compile time api hs_compile_lit() and hs_compile_lit_multi()
to handle pure literal pattern sets. Corresponding option --literal-on
is added for hyperscan testing suites. Extended parameters and part of
flags are not supported for this api.

src/fdr/fdr_confirm_compile.cpp

@@ -87,7 +87,6 @@ void fillLitInfo(const vector<hwlmLiteral> &lits, vector<LitInfo> &tmpLitInfo,
         info.flags = flags;
         info.size = verify_u8(max(lit.msk.size(), lit.s.size()));
         info.groups = lit.groups;
-        info.pure = lit.pure;
 
         // these are built up assuming a LE machine
         CONF_TYPE msk = all_ones;