97381792ac
Also move these optimization rules to cprop.isle; it's where all the other similar rules are. Like the other cprop rules, these can subsume any other rules. We can't do better than reducing an expression to a constant. The new i64_sextend_imm64 and u64_uextend_imm64 constructors are useful helpers to clean up other code. I applied them to `imm64_icmp` while I was here, as well as using the existing `ty_mask` helper to clean up `imm64_masked`.
This crate contains the core Cranelift code generator. It translates code from an intermediate representation into executable machine code.