Update ext/sodium preprocessor macro help texts (#15270)

The sodium extension was initially named "libsodium" in PECL and was
renamed to sodium when it was bundled to php-src. The HAVE_LIBSODIUMLIB
symbol here could indicate that PHP extension sodium is available.

Otherwise the macro is not used in the current code base. Header
php_libsodium.h became "installed"/public as of PHP-8.4.

[skip ci]

Author: petk

ext/sodium/config.m4

@@ -9,7 +9,8 @@ if test "$PHP_SODIUM" != "no"; then
   PHP_EVAL_INCLINE([$LIBSODIUM_CFLAGS])
   PHP_EVAL_LIBLINE([$LIBSODIUM_LIBS], [SODIUM_SHARED_LIBADD])
 
-  AC_DEFINE(HAVE_LIBSODIUMLIB, 1, [ ])
+  AC_DEFINE([HAVE_LIBSODIUMLIB], [1],
+    [Define to 1 if the PHP extension 'sodium' is available.])
 
   SODIUM_COMPILER_FLAGS="$LIBSODIUM_CFLAGS"
 

ext/sodium/config.w32

@@ -5,7 +5,7 @@ ARG_WITH("sodium", "for libsodium support", "no");
 if (PHP_SODIUM != "no") {
 	if (CHECK_LIB("libsodium.lib", "sodium", PHP_SODIUM) && CHECK_HEADER_ADD_INCLUDE("sodium.h", "CFLAGS_SODIUM")) {
 		EXTENSION("sodium", "libsodium.c sodium_pwhash.c");
-		AC_DEFINE('HAVE_LIBSODIUMLIB', 1 , 'Have the Sodium library');
+		AC_DEFINE('HAVE_LIBSODIUMLIB', 1 , "Define to 1 if the PHP extension 'sodium' is available.");
 		PHP_INSTALL_HEADERS("ext/sodium", "php_libsodium.h");
 	} else {
 		WARNING("libsodium not enabled; libraries and headers not found");