[WIP] Switch to the cg_ssa codegen coordinator #1824

Job	Run time
abi_cafe (macos-latest, aarch64-apple-darwin)	4m 8s
abi_cafe (ubuntu-latest, x86_64-unknown-linux-gnu)	5m 47s
abi_cafe (ubuntu-24.04-arm, aarch64-unknown-linux-gnu)	6m 8s
abi_cafe (windows-latest, x86_64-pc-windows-msvc)	11m 25s
abi_cafe (macos-15-intel, x86_64-apple-darwin)	13m 22s
	40m 50s

Provide feedback