move xmlunicode.c to correct location in build script

Author: neelsani

build.zig

@@ -181,7 +181,7 @@ pub fn build(b: *std.Build) void {
     if (output) xml_lib.root_module.addCSourceFile(.{ .file = upstream.path("xmlsave.c"), .flags = xml_flags });
     if (pattern) xml_lib.root_module.addCSourceFile(.{ .file = upstream.path("pattern.c"), .flags = xml_flags });
     if (reader) xml_lib.root_module.addCSourceFile(.{ .file = upstream.path("xmlreader.c"), .flags = xml_flags });
-    if (regexps) xml_lib.root_module.addCSourceFiles(.{ .files = &.{"xmlregexp.c"}, .root = upstream.path(""), .flags = xml_flags });
+    if (regexps) xml_lib.root_module.addCSourceFiles(.{ .files = &.{"xmlregexp.c", "xmlunicode.c"}, .root = upstream.path(""), .flags = xml_flags });
     if (relaxng) xml_lib.root_module.addCSourceFile(.{ .file = upstream.path("relaxng.c"), .flags = xml_flags });
     if (schemas) xml_lib.root_module.addCSourceFiles(.{ .files = &.{ "xmlschemas.c", "xmlschemastypes.c" }, .root = upstream.path(""), .flags = xml_flags });
     if (schematron) xml_lib.root_module.addCSourceFile(.{ .file = upstream.path("schematron.c"), .flags = xml_flags });
@@ -229,7 +229,6 @@ pub const xml_src: []const []const u8 = &.{
     "xmlIO.c",
     "xmlmemory.c",
     "xmlstring.c",
-    "xmlunicode.c",
 };
 
 pub const xml_flags: []const []const u8 = &.{