* mlibc/include/stdint.h (size_t)[!__MES_SIZE_T]: Declare.
* mlibc/include: Neutralize include guards before #include_next. Fixes compiling tinycc on Debian GNU/Linux.
* mlibc/include/alloca.h: New file. * mlibc/include/stdint.h: New file. * mlibc/include/inttypes.h: Remove definitionss, include stdint.h.