Merge pull request #284 from k-okada/fix_free

In eus.h, macro to define free() to substitute cfree() is added for Linux and Linux64, since cfree() is made obsolete in 2018.

Author: k-okada

lisp/c/eus.h

@@ -41,7 +41,7 @@ typedef float eusfloat_t;
 #define	USE_STDARG
 #endif
 
-#ifdef Darwin
+#if defined(Darwin) || defined(Linux) || defined(Linux64)
 #define cfree free
 #endif