Fix bug with passing shared libraries to ldc2 (D/dlang)

[exhu]

LLM usage disclosure: i've consulted google's gemini to find out the place where and how to write a unit test here since I don't write python these days.

Current meson produces invalid command to build Dlang app that depends on an internal static C library built with meson that depends on a system shared library.

I've added a minimal test case to demonstrate, but it depends on blkid library and pkg-config (i've tried other libraries like zlib but it's unreliable, looks like ldc2 sorts the inputs, and there's no such problem with shared libraries built as a subproject). Overall I'm not sure if it's acceptable to put a test into this directory because it depends on a library to be installed.

This is the error before fix:

meson setup _build .

18 so dependency via clib (fix-ldc2-so-link)> ninja -C _build
ninja: Entering directory `_build'
[4/4] Linking target prog
FAILED: prog 
ldc2  -of=prog prog.p/main.d.o -L=--allow-shlib-undefined -link-defaultlib-shared -L=clib/libclib.a /usr/lib/x86_64-linux-gnu/libblkid.so
/usr/bin/ld: clib/libclib.a.p/clib.c.o: in function `clib_call_blkid':
/home/yur/projects/meson/test cases/d/18 so dependency via clib/_build/../clib/clib.c:5:(.text+0xe): undefined reference to `blkid_init_debug'
collect2: error: ld returned 1 exit status
Error: /usr/bin/cc failed with status: 1
ninja: build stopped: subcommand failed.

The fix is that "/usr/lib/x86_64-linux-gnu/libblkid.so" must be prefixed with "-L=" so that ldc2 passes it to the linker after the static library that references libblkid, otherwise it's passed before and thus unresolved reference.