TinyC Compiler "include file pthread.h not found"

Question

Having read the changelog and some mail archives, pthread is supposed to be supported by TinyC Compiler (TCC) since 0.9.26

https://bellard.org/tcc/changelog.html

version 0.9.26:

User interface:
- -pthread option (same as -D_REENTRANT -lpthread) (Henry Kroll III)

I'm using 0.9.27 Windows 64bit

What I don't get is the actual pthread.h include file is nowhere to found as per error in the question title.

and along with error pthread library not found.