[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 #7 from Ilya Leoshkevich <iii at linux dot ibm.com> ---
Would it be OK then to replace last arguments of functions with
__attribute__((sentinel)) from NULLs to nullptrs? I can make a patch for this.