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/rose/rose_build_matchers.cpp

@@ -727,7 +727,6 @@ void addFragmentLiteral(const RoseBuildImpl &build, MatcherProto &mp,
 
     const auto &s_final = lit_final.get_string();
     bool nocase = lit_final.any_nocase();
-    bool pure = f.s.get_pure();
 
     DEBUG_PRINTF("id=%u, s='%s', nocase=%d, noruns=%d, msk=%s, cmp=%s\n",
                  f.fragment_id, escapeString(s_final).c_str(), (int)nocase,
@@ -741,7 +740,7 @@ void addFragmentLiteral(const RoseBuildImpl &build, MatcherProto &mp,
     const auto &groups = f.groups;
 
     mp.lits.emplace_back(move(s_final), nocase, noruns, f.fragment_id,
-                         groups, msk, cmp, pure);
+                         groups, msk, cmp);
 }
 
 static