feature(parser): empty decl (#69)

gen/gsc/parser.ypp

@@ -276,12 +276,16 @@ root
     ;
 
 program
-    : program inline
+    : program SEMICOLON
+        { $$ = std::move($1); }
+    | program inline
         { $$ = std::move($1); }
     | program include
         { $$ = std::move($1); $$->includes.push_back(std::move($2)); }
     | program declaration
         { $$ = std::move($1); $$->declarations.push_back(std::move($2)); }
+    | SEMICOLON
+        { $$ = make_program(@$); }
     | inline
         { $$ = make_program(@$); }
     | include

src/gsc/parser.hpp

@@ -5008,9 +5008,9 @@ switch (yykind)
     /// Constants.
     enum
     {
-      yylast_ = 2334,     ///< Last index in yytable_.
+      yylast_ = 2375,     ///< Last index in yytable_.
       yynnts_ = 92,  ///< Number of nonterminal symbols.
-      yyfinal_ = 22 ///< Termination state number.
+      yyfinal_ = 23 ///< Termination state number.
     };