move required_consts check to general post-mono-check function

compiler/rustc_codegen_ssa/src/mir/mod.rs

@@ -1,4 +1,5 @@
 use crate::base;
+use crate::errors;
 use crate::traits::*;
 use rustc_index::bit_set::BitSet;
 use rustc_index::IndexVec;
@@ -212,24 +213,21 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
 
     fx.per_local_var_debug_info = fx.compute_per_local_var_debug_info(&mut start_bx);
 
-    // Evaluate all required consts; codegen later assumes that CTFE will never fail.
-    let mut all_consts_ok = true;
-    for const_ in &mir.required_consts {
-        if let Err(err) = fx.eval_mir_constant(const_) {
-            all_consts_ok = false;
-            match err {
-                // errored or at least linted
-                ErrorHandled::Reported(_) => {}
-                ErrorHandled::TooGeneric => {
-                    span_bug!(const_.span, "codegen encountered polymorphic constant: {:?}", err)
-                }
-            }
+    // Rust post-monomorphization checks; we later rely on them.
+    match mir.post_mono_checks(cx.tcx(), ty::ParamEnv::reveal_all(), |c| Ok(fx.monomorphize(c))) {
+        Ok(()) => {}
+        Err(ErrorHandled::TooGeneric(span)) => {
+            cx.tcx().sess.diagnostic().emit_bug(errors::PolymorphicConstantTooGeneric { span });
+        }
+        Err(ErrorHandled::Reported(info, span)) => {
+            if !info.is_tainted_by_errors() {
+                cx.tcx().sess.emit_err(errors::ErroneousConstant { span });
+            }
+            // This IR shouldn't ever be emitted, but let's try to guard against any of this code
+            // ever running.
+            start_bx.abort();
+            return;
         }
-    }
-    if !all_consts_ok {
-        // We leave the IR in some half-built state here, and rely on this code not even being
-        // submitted to LLVM once an error was raised.
-        return;
     }
 
     let memory_locals = analyze::non_ssa_locals(&fx);