Drop bogus ext/libxml dependency on ext/iconv (GH-16801)

There is no such dependency; only libxml2 depends on libiconv.  So when
php_libxml.dll is built, it needs to be linked against libiconv, or,
when ext/iconv has been configured as static extension, against
php8.dll.

Author: cmb69

ext/libxml/config.w32

@@ -4,10 +4,9 @@ ARG_WITH("libxml", "LibXML support", "yes");
 
 if (PHP_LIBXML == "yes") {
 	if (CHECK_LIB("libxml2_a_dll.lib;libxml2_a.lib", "libxml") &&
-			CHECK_LIB("libiconv_a.lib;iconv_a.lib;libiconv.lib;iconv.lib", "libxml") &&
+			((PHP_ICONV != "no" && !PHP_ICONV_SHARED) || CHECK_LIB("libiconv_a.lib;iconv_a.lib;libiconv.lib;iconv.lib", "libxml")) &&
 			CHECK_HEADER_ADD_INCLUDE("libxml/parser.h", "CFLAGS_LIBXML", PHP_PHP_BUILD + "\\include\\libxml2") &&
-			CHECK_HEADER_ADD_INCLUDE("libxml/tree.h", "CFLAGS_LIBXML", PHP_PHP_BUILD + "\\include\\libxml2") &&
-			ADD_EXTENSION_DEP('libxml', 'iconv')) {
+			CHECK_HEADER_ADD_INCLUDE("libxml/tree.h", "CFLAGS_LIBXML", PHP_PHP_BUILD + "\\include\\libxml2")) {
 
 		if (GREP_HEADER("libxml/xmlversion.h", "#define\\s+LIBXML_VERSION\\s+(\\d+)", PHP_PHP_BUILD + "\\include\\libxml2") &&
 				+RegExp.$1 >= 20904) {