Do not require ctype/stdio if not needed

libsolidity/inlineasm/AsmParser.cpp

@@ -26,7 +26,7 @@
 
 #include <boost/algorithm/string.hpp>
 
-#include <ctype.h>
+#include <cctype>
 #include <algorithm>
 
 using namespace std;

libsolidity/parsing/Parser.cpp

@@ -20,7 +20,7 @@
  * Solidity parser.
  */
 
-#include <ctype.h>
+#include <cctype>
 #include <vector>
 #include <libevmasm/SourceLocation.h>
 #include <libsolidity/parsing/Parser.h>