build failure: malloc_np.h missing

[Thomas Klausner <wiz%NetBSD.org@localhost>]

Hi!

With latest source, I see

--- Process.lo ---
In file included from /usr/src/tools/llvm-lib/libLLVMSupport/../../llvm/../../external/apache2/llvm/lib/../dist/llvm/lib/Support/Process.cpp:108:
/usr/src/tools/llvm-lib/libLLVMSupport/../../llvm/../../external/apache2/llvm/lib/../dist/llvm/lib/Support/Unix/Process.inc:38:10: fatal error: malloc_np.h: No such file or directory
   38 | #include <malloc_np.h>
      |          ^~~~~~~~~~~~~
compilation terminated.

when building with

build.sh -j 32 -x -V MKDEBUG=yes -V MKDEBUGLIB=yes -T /usr/obj/tools.gcc -m amd64 -O /usr/obj/src.amd64 -D /usr/obj/amd64.gcc.20240926 -R /usr/obj/amd64.gcc.20240926.release distribution

It's repeatable, on two consecutive tries.
 Thomas