[SOL] Implement return instruction #309

Job	Run time
abi-dump-setup	1m 23s
Test llvm,clang,libclc / Lit Tests (ubuntu-22.04)	47m 7s
Test lld / Lit Tests (ubuntu-22.04)	9m 49s
Build lldb / Lit Tests (ubuntu-22.04)	21m 12s
Test lld / Lit Tests (windows-2019)	1m 52s
Build lldb / Lit Tests (windows-2019)	1m 53s
Test lld / Lit Tests (macOS-latest)	8m 51s
Build lldb / Lit Tests (macOS-latest)	14m 22s
Test llvm,clang,libclc / Lit Tests (windows-2019)	2m 21s
Test llvm,clang,libclc / Lit Tests (macOS-latest)	1h 11m 26s
abi-dump (build-baseline)	31m 45s
abi-dump (build-latest)	32m 21s
abi-compare	30s
	4h 4m 52s

Provide feedback