Remove redundant _WIN32 compile definitions (#14458)

_WIN32 is defined by all compilers on Windows when targeting 32-bit ARM,
64-bit ARM, x86, or x64. This removes redundant definition in ext/zip
and erroneous CFLAG_ENCHANT variable (should be CFLAGS_ENCHANT).

Author: petk

ext/enchant/config.w32

@@ -18,7 +18,6 @@ if (PHP_ENCHANT == "yes") {
 			EXTENSION("enchant", "enchant.c");
 			AC_DEFINE('HAVE_ENCHANT', 1, 'Have Enchant support', false);
 			AC_DEFINE('HAVE_ENCHANT_GET_VERSION', 1);
-			ADD_FLAG("CFLAG_ENCHANT", "/D _WIN32");
 		}
 	} else {
 		WARNING('Could not find enchant.h; skipping');

ext/zip/config.w32

@@ -17,7 +17,7 @@ if (PHP_ZIP != "no") {
 		}
 
 		AC_DEFINE('HAVE_ZIP', 1);
-		ADD_FLAG("CFLAGS_ZIP", "/D _WIN32 /D HAVE_SET_MTIME /D HAVE_ENCRYPTION /D HAVE_LIBZIP_VERSION /D HAVE_PROGRESS_CALLBACK /D HAVE_CANCEL_CALLBACK /D HAVE_METHOD_SUPPORTED /D LZMA_API_STATIC");
+		ADD_FLAG("CFLAGS_ZIP", "/D HAVE_SET_MTIME /D HAVE_ENCRYPTION /D HAVE_LIBZIP_VERSION /D HAVE_PROGRESS_CALLBACK /D HAVE_CANCEL_CALLBACK /D HAVE_METHOD_SUPPORTED /D LZMA_API_STATIC");
 	} else {
 		WARNING("zip not enabled; libraries and headers not found");
 	}