Rename the ConstS::val field as kind.

And likewise for the `Const::val` method.

Because its type is called `ConstKind`. Also `val` is a confusing name
because `ConstKind` is an enum with seven variants, one of which is
called `Value`. Also, this gives consistency with `TyS` and `PredicateS`
which have `kind` fields.

The commit also renames a few `Const` variables from `val` to `c`, to
avoid confusion with the `ConstKind::Value` variant.

Author: nnethercote

src/base.rs

@@ -710,7 +710,7 @@ fn codegen_stmt<'tcx>(
                     let times = fx
                         .monomorphize(times)
                         .eval(fx.tcx, ParamEnv::reveal_all())
-                        .val()
+                        .kind()
                         .try_to_bits(fx.tcx.data_layout.pointer_size)
                         .unwrap();
                     if operand.layout().size.bytes() == 0 {

src/constant.rs

@@ -45,7 +45,7 @@ pub(crate) fn check_constants(fx: &mut FunctionCx<'_, '_, '_>) -> bool {
             ConstantKind::Ty(ct) => ct,
             ConstantKind::Val(..) => continue,
         };
-        match const_.val() {
+        match const_.kind() {
             ConstKind::Value(_) => {}
             ConstKind::Unevaluated(unevaluated) => {
                 if let Err(err) =
@@ -126,7 +126,7 @@ pub(crate) fn codegen_constant<'tcx>(
         ConstantKind::Ty(ct) => ct,
         ConstantKind::Val(val, ty) => return codegen_const_value(fx, val, ty),
     };
-    let const_val = match const_.val() {
+    let const_val = match const_.kind() {
         ConstKind::Value(const_val) => const_val,
         ConstKind::Unevaluated(ty::Unevaluated { def, substs, promoted })
             if fx.tcx.is_static(def.did) =>
@@ -469,7 +469,7 @@ pub(crate) fn mir_operand_get_const_val<'tcx>(
     match operand {
         Operand::Constant(const_) => match const_.literal {
             ConstantKind::Ty(const_) => {
-                fx.monomorphize(const_).eval(fx.tcx, ParamEnv::reveal_all()).val().try_to_value()
+                fx.monomorphize(const_).eval(fx.tcx, ParamEnv::reveal_all()).kind().try_to_value()
             }
             ConstantKind::Val(val, _) => Some(val),
         },