abi: s/ScalableVector/SimdScalableVector

Renaming to remove any ambiguity as to what "vector" refers to in this
context

compiler/rustc_const_eval/src/interpret/place.rs

@@ -904,7 +904,7 @@ pub(super) fn copy_op_no_validate(
             }
             // Everything else can only exist in memory anyway, so it doesn't matter.
             BackendRepr::SimdVector { .. }
-            | BackendRepr::ScalableVector { .. }
+            | BackendRepr::SimdScalableVector { .. }
             | BackendRepr::Memory { .. } => true,
         };
 

compiler/rustc_const_eval/src/interpret/validity.rs

@@ -1331,7 +1331,7 @@ fn visit_value(&mut self, val: &PlaceTy<'tcx, M::Provenance>) -> InterpResult<'t
                     self.visit_scalar(b, b_layout)?;
                 }
             }
-            BackendRepr::SimdVector { .. } | BackendRepr::ScalableVector { .. } => {
+            BackendRepr::SimdVector { .. } | BackendRepr::SimdScalableVector { .. } => {
                 // No checks here, we assume layout computation gets this right.
                 // (This is harder to check since Miri does not represent these as `Immediate`. We
                 // also cannot use field projections since this might be a newtype around a vector.)

compiler/rustc_const_eval/src/util/check_validity_requirement.rs

@@ -119,7 +119,7 @@ fn check_validity_requirement_lax<'tcx>(
             }
             BackendRepr::SimdVector { element: s, count } => count == 0 || scalar_allows_raw_init(s),
             BackendRepr::Memory { .. } => true, // Fields are checked below.
-            BackendRepr::ScalableVector { element, .. } => scalar_allows_raw_init(element),
+            BackendRepr::SimdScalableVector { element, .. } => scalar_allows_raw_init(element),
         };
 
     if !valid {