Reuse strcasestr implementation from libmagic

Author: weltling

ext/fileinfo/config.w32

@@ -9,7 +9,7 @@ if (PHP_FILEINFO != 'no') {
 			encoding.c fsmagic.c funcs.c \
 			is_tar.c magic.c print.c \
 			readcdf.c softmagic.c der.c \
-			buffer.c";
+			strcasestr.c buffer.c";
 
 	EXTENSION('fileinfo', 'fileinfo.c', true, "/I" + configure_module_dirname + "/libmagic /I" + configure_module_dirname);
 	ADD_SOURCES(configure_module_dirname + '\\libmagic', LIBMAGIC_SOURCES, "fileinfo");

ext/fileinfo/libmagic/readcdf.c

@@ -79,10 +79,6 @@ static const struct nv {
 	{ NULL,				NULL,			},
 };
 
-#ifdef PHP_WIN32
-# define strcasestr strstr
-#endif
-
 static const struct cv {
 	uint64_t clsid[2];
 	const char *mime;