use GlobalId in eval_to_valtree query and introduce query for valtree_to_const_val

compiler/rustc_mir_build/src/build/misc.rs

@@ -3,7 +3,6 @@
 
 use crate::build::Builder;
 
-use rustc_middle::mir;
 use rustc_middle::mir::*;
 use rustc_middle::ty::{self, Ty};
 use rustc_span::{Span, DUMMY_SP};
@@ -26,11 +25,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
 
     /// Convenience function for creating a literal operand, one
     /// without any user type annotation.
-    crate fn literal_operand(
-        &mut self,
-        span: Span,
-        literal: mir::ConstantKind<'tcx>,
-    ) -> Operand<'tcx> {
+    crate fn literal_operand(&mut self, span: Span, literal: ConstantKind<'tcx>) -> Operand<'tcx> {
         let constant = Box::new(Constant { span, user_ty: None, literal });
         Operand::Constant(constant)
     }