cranelift: Remove booleans (#5031)

Remove the boolean types from cranelift, and the associated instructions breduce, bextend, bconst, and bint. Standardize on using 1/0 for the return value from instructions that produce scalar boolean results, and -1/0 for boolean vector elements.

Fixes #3205

Co-authored-by: Afonso Bordado <afonso360@users.noreply.github.com>
Co-authored-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Co-authored-by: Chris Fallin <chris@cfallin.org>

cranelift/codegen/src/isa/s390x/abi.rs

@@ -94,7 +94,6 @@ pub type S390xCallee = Callee<S390xMachineDeps>;
 fn in_int_reg(ty: Type) -> bool {
     match ty {
         types::I8 | types::I16 | types::I32 | types::I64 | types::R64 => true,
-        types::B1 | types::B8 | types::B16 | types::B32 | types::B64 => true,
         _ => false,
     }
 }