[Bug c++/95700] read-md.c: "missing sentinel in function call" when building gcc with musl

[iii at linux dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95700

--- Comment #4 from Ilya Leoshkevich <iii at linux dot ibm.com> ---
Created attachment 48740
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48740&action=edit
preprocessed output

In the preprocessed output I see that gcc's stddef.h is used, but most likely
`#define NULL 0L` comes from some other musl header, since musl defines it in
like 8 places.