Merge syntax.{h,cc} into opt.{h,cc} and get rid of Stx struct.

Syntax file handling is completely tied up with option handling, there's
no need to maintain separate infrastructure for syntax configurations.

CMakeLists.txt

@@ -147,7 +147,6 @@ set(re2c_sources
     src/codegen/pass4_render.cc
     src/options/opt.cc
     src/options/symtab.cc
-    src/options/syntax.cc
     src/nfa/re_to_nfa.cc
     src/adfa/adfa.cc
     src/debug/dump_adfa.cc
@@ -482,7 +481,6 @@ if (RE2C_BUILD_LIBS)
         src/parse/input.cc
         src/options/opt.cc
         src/options/symtab.cc
-        src/options/syntax.cc
         src/cfg/cfg.cc
         src/cfg/compact.cc
         src/cfg/dce.cc

Makefile.am

@@ -24,7 +24,6 @@ re2c_HDR = \
 	src/codegen/helpers.h \
 	src/options/opt.h \
 	src/options/symtab.h \
-	src/options/syntax.h \
 	src/adfa/adfa.h \
 	src/cfg/cfg.h \
 	src/dfa/closure_leftmost.h \
@@ -75,7 +74,6 @@ re2c_SRC = \
 	src/codegen/pass4_render.cc \
 	src/options/opt.cc \
 	src/options/symtab.cc \
-	src/options/syntax.cc \
 	src/nfa/re_to_nfa.cc \
 	src/adfa/adfa.cc \
 	src/debug/dump_adfa.cc \

Makefile.lib.am

@@ -15,7 +15,6 @@ libre2c_la_HDR = \
 	src/codegen/code.h \
 	src/options/opt.h \
 	src/options/symtab.h \
-	src/options/syntax.h \
 	src/adfa/adfa.h \
 	src/cfg/cfg.h \
 	src/dfa/closure_leftmost.h \
@@ -72,7 +71,6 @@ libre2c_la_SRC = \
 	src/parse/input.cc \
 	src/options/opt.cc \
 	src/options/symtab.cc \
-	src/options/syntax.cc \
 	src/cfg/cfg.cc \
 	src/cfg/compact.cc \
 	src/cfg/dce.cc \

bootstrap/src/parse/conf_lexer.cc

@@ -8802,7 +8802,7 @@ Ret Input::lex_syntax_file(Opt& opts) {
 	++cur;
 	cur -= 5;
 #line 654 "../src/parse/conf_lexer.re"
-	{ if (conf_parse(*this, opts, opts.stx) != 0) return Ret::FAIL; goto start; }
+	{ if (conf_parse(*this, opts) != 0) return Ret::FAIL; goto start; }
 #line 8807 "src/parse/conf_lexer.cc"
 yy1614:
 	++cur;