x11-misc/shared-mime-info-2.4 fails to build with dev-libs/libxml2-2.12.0 and clang-17

Building x11-misc/shared-mime-info with both libxml2-2.12.0 and clang-17 fails to work with 2 errors (implicit function declaration, and incompatible integer to pointer conversion)

The first became an error in clang 16 and the second in clang 15 I believe.

These errors don't occur with the previous version of libxml2, and the package builds successfully if I enable -Wno-error=int-conversion -Wno-error=implicit-function-declaration as CFLAGS.

Reported downstream: https://bugs.gentoo.org/917561