regex: Move the defines to a config header and include it unconditionally

CMakeLists.txt

@@ -32,7 +32,6 @@ ELSE()
 	# Windows doesn't understand POSIX regex on its own
 	INCLUDE_DIRECTORIES(deps/regex)
 	SET(SRC_REGEX deps/regex/regex.c)
-	ADD_DEFINITIONS(-DGAWK -DNO_MBSUPPORT)
 ENDIF()
 
 IF (ZLIB_FOUND)

deps/regex/config.h

+#ifndef _REGEX_CONFIG_H_
+#define _REGEX_CONFIG_H_
+
+# define GAWK
+# define NO_MBSUPPORT
+
+#endif

deps/regex/regex.c

@@ -18,9 +18,7 @@
    Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    02110-1301 USA.  */
 
-#ifdef HAVE_CONFIG_H
 #include "config.h"
-#endif
 
 /* Make sure noone compiles this code with a C++ compiler.  */
 #ifdef __cplusplus