tomlc99 vendored from https://github.com/cktan/tomlc99 @ 29076dfd095bbbbd50a3c1b2760d29f4b83e74ac

The vendored toml.c and toml.h are kept byte-for-byte identical to upstream.
On MSVC, recompiler/CMakeLists.txt disables C4244 and C4267 only for toml.c:
the upstream parser intentionally narrows buffer lengths and pointer
differences to its int-sized public/internal interfaces. First-party sources
retain the normal warning policy.
