xdg-decoration-unstable-v1 protocol xml references xdg_toplevel interface but doesn't define it

I'm a novice w.r.t. this stuff, but from a glance at these protocol xml files, I gather only the wl_ prefixed interfaces needn't be defined (guessing they are picked up from the wayland library xml)? Ran into this while running the tests because I'm using the LLVM LLD linker. Apparently with the BFD linker from binutils this issue isn't exposed (if it is in fact an issue). Filing this here even though it might be a problem with the wayland-scanner (in that it should be picking up the definition from the xdg-shell xml where the interface is defined) if I'm understanding the process correctly.

Here is the output from the test failure

66/77 test-build-pedantic-unstable_xdg_decoration_xdg_decoration_unstable_v1_xml                                         FAIL            0.05s   exit status 127
>>> MALLOC_PERTURB_=106 /var/tmp/paludis/build/sys-libs-wayland-protocols-1.21/work/_build/tests/test-build-pedantic-unstable_xdg_decoration_xdg_decoration_unstable_v1_xml
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stderr:
/var/tmp/paludis/build/sys-libs-wayland-protocols-1.21/work/_build/tests/test-build-pedantic-unstable_xdg_decoration_xdg_decoration_unstable_v1_xml: symbol lookup error: /var/tmp/paludis/build/sys-libs-wayland-protocols-1.21/work/_build/tests/test-build-pedantic-unstable_xdg_decoration_xdg_decoration_unstable_v1_xml: undefined symbol: xdg_toplevel_interface