Remove TRUE/FALSE definition in C sources. (Reported by #282 but not applied.)

src/re.c

@@ -26,14 +26,6 @@
 #define MKARG_B(c)    (((c) & 0xff) << 16)
 #define MKARG_C(c)    (((c) & 0xff) <<  8)
 
-#ifndef FALSE
-#define FALSE   0
-#endif
-
-#ifndef TRUE
-#define TRUE    1
-#endif
-
 #define ARG_REG_OPTION_MASK \
     (ONIG_OPTION_IGNORECASE|ONIG_OPTION_MULTILINE|ONIG_OPTION_EXTEND)
 #define ARG_ENCODING_FIXED    16

src/regenc.c

@@ -32,14 +32,6 @@
 #include <string.h>
 #include "regint.h"
 
-#ifndef FALSE
-#define FALSE   0
-#endif
-
-#ifndef TRUE
-#define TRUE    1
-#endif
-
 OnigEncoding OnigEncDefaultCharEncoding = ONIG_ENCODING_INIT_DEFAULT;
 
 extern int

src/string.c

@@ -22,14 +22,6 @@
 #include "st.h"
 #endif //ENABLE_REGEXP
 
-#ifndef FALSE
-#define FALSE   0
-#endif
-
-#ifndef TRUE
-#define TRUE    1
-#endif
-
 const char mrb_digitmap[] = "0123456789abcdefghijklmnopqrstuvwxyz";
 
 #ifdef ENABLE_REGEXP