lang/fpc-wasip1threads-devel: New port: Free Pascal wasm wasip1threads compiler (devel)

FPC supports three Wasm compilation targets: WASIp1 (WASI 0.1, also known as
WASI Preview 1), WASIp1threads (WASI 0.1 with the wasi-threads proposal) and
Embedded. FPC's Wasm support adds to FPC's already extensive list of
compilation targets, potentially allowing Pascal programs to run in even more
environments than they already do.

PR: 297129