Add enum for can_access_statics boolean

`/*can_access_statics:*/ false` is one of the ways to do this, but not
the one I like.

compiler/rustc_const_eval/src/util/check_validity_requirement.rs

@@ -2,7 +2,7 @@ use rustc_middle::ty::layout::{LayoutCx, LayoutError, LayoutOf, TyAndLayout, Val
 use rustc_middle::ty::{ParamEnv, ParamEnvAnd, Ty, TyCtxt};
 use rustc_target::abi::{Abi, FieldsShape, Scalar, Variants};
 
-use crate::const_eval::{CheckAlignment, CompileTimeInterpreter};
+use crate::const_eval::{CanAccessStatics, CheckAlignment, CompileTimeInterpreter};
 use crate::interpret::{InterpCx, MemoryKind, OpTy};
 
 /// Determines if this type permits "raw" initialization by just transmuting some memory into an
@@ -44,8 +44,7 @@ fn might_permit_raw_init_strict<'tcx>(
     tcx: TyCtxt<'tcx>,
     kind: ValidityRequirement,
 ) -> Result<bool, LayoutError<'tcx>> {
-    let machine =
-        CompileTimeInterpreter::new(/*can_access_statics:*/ false, CheckAlignment::Error);
+    let machine = CompileTimeInterpreter::new(CanAccessStatics::No, CheckAlignment::Error);
 
     let mut cx = InterpCx::new(tcx, rustc_span::DUMMY_SP, ParamEnv::reveal_all(), machine);