First hermetic IVerilog

Linux version built at v12-branch commit 2cc7538.
Darwin version built at v12-branch commit 2cc7538.

iverilog-linux-x86_64-20240314_1 was rebuilt at v12-branch commit 3a9d2e7 to get a version with older dependencies compatible with Rocky 9.

iverilog-linux-x86_64-20240318_3 was rebuilt at v12-branch commit 4bbe728 to get a version with older dependencies compatible with Rocky 8.