Looks interesting.

In fact, both functions have the same body:

void LibRaw::vc5_dng_load_raw_placeholder()
{
    // placeholder only, real decoding implemented in GPR SDK
    throw LIBRAW_EXCEPTION_UNSUPPORTED_FORMAT;
}
void LibRaw::jxl_dng_load_raw_placeholder()
{
  // placeholder only, real decoding implemented in DNG SDK
  throw LIBRAW_EXCEPTION_UNSUPPORTED_FORMAT;
}

Looks like Visual studio detects this, compiles as single function, so
else if (load_raw == &LibRaw::vc5_dng_load_raw_placeholder)
and
else if (load_raw == &LibRaw::jxl_dng_load_raw_placeholder)
Are both true....

Looks like
1) these functions should be separated in additional code unit
2) All optimizations should be disabled at least for common compilers (gcc, clang, visual studio).