Fix the dependency by making the stamp an actual (yet empty/no-op)
header file which is included by all generated source file. This way, we
ensure that meson rebuild .o files when the .pdb sources are changed.
This is the second solution proposed by eli-schwartz here:
https://github.com/mesonbuild/meson/issues/10196#issuecomment-1080053413
on behalf of plug-in authors who have no style or can't type.
Instead, simply reject non-canonical procedure names and remove all
code that keeps aroud the original non-canonical shit just to pass it
back to the plug-in.
Such comment should not be included in the general PDB
documentation as it is specific to the C bindings and can
be easily added by the pdbgen infrastructure.
This reverts commit c9888f2222.
