refactor, libc made optional

Player/amalgam.c

@@ -2,7 +2,17 @@
     Amalgamation file, compiling all in single unit.
 */
 
+#include "../Common/def.h"
 #include "../Common/fix.c"
 #include "../Common/lzw.c"
 #include "../Common/mat.c"
 #include "./draw.c"
+
+#if COM_DEF_TARGET == COM_DEF_TARGET_LINUX
+#include "../Common/Std/libc.c"
+#include "../Common/Timer/posix.c"
+#include "./Display/x11.c"
+#include "./Main/linux.c"
+#elif COM_DEF_TARGET == COM_DEF_TARGET_WASM
+#include "../Common/Std/stub.c"
+#endif