Remove layouts from the mono AST for expects

This actually isn't needed, because the backends must lookup the layout
from the environment anyway. So it's enough to lookup the symbol and
find its layout, there is no need to additionally store it.

crates/compiler/gen_llvm/src/llvm/build.rs

@@ -2586,7 +2586,6 @@ pub fn build_exp_stmt<'a, 'ctx, 'env>(
             condition: cond_symbol,
             region,
             lookups,
-            layouts: _,
             remainder,
         } => {
             let bd = env.builder;
@@ -2655,7 +2654,6 @@ pub fn build_exp_stmt<'a, 'ctx, 'env>(
             condition: cond_symbol,
             region,
             lookups,
-            layouts: _,
             remainder,
         } => {
             let bd = env.builder;