Make the randomize feature of rustc_abi additive

Author: HKalbasi

Diff for: compiler/rustc_abi/src/lib.rs

@@ -75,7 +75,7 @@ pub struct ReprOptions {
     pub int: Option<IntegerType>,
     pub align: Option<Align>,
     pub pack: Option<Align>,
-    pub flags: ReprFlags,
+    flags: ReprFlags,
     #[cfg(feature = "randomize")]
     /// The seed to be used for randomizing a type's layout
     ///
@@ -88,6 +88,24 @@ pub struct ReprOptions {
 }
 
 impl ReprOptions {
+    pub fn new(int: Option<IntegerType>, align: Option<Align>, pack: Option<Align>) -> Self {
+        Self { int, align, pack, ..ReprOptions::default() }
+    }
+
+    pub fn with_flags(mut self, flags: ReprFlags) -> Self {
+        self.flags = flags;
+        self
+    }
+
+    #[cfg(feature = "randomize")]
+    pub fn with_shuffle_seed(
+        mut self,
+        field_shuffle_seed: rustc_data_structures::stable_hasher::Hash64,
+    ) -> Self {
+        self.field_shuffle_seed = field_shuffle_seed;
+        self
+    }
+
     #[inline]
     pub fn simd(&self) -> bool {
         self.flags.contains(ReprFlags::IS_SIMD)

Diff for: compiler/rustc_middle/src/ty/mod.rs

@@ -2076,7 +2076,9 @@ impl<'tcx> TyCtxt<'tcx> {
             flags.insert(ReprFlags::IS_LINEAR);
         }
 
-        ReprOptions { int: size, align: max_align, pack: min_pack, flags, field_shuffle_seed }
+        ReprOptions::new(size, max_align, min_pack)
+            .with_flags(flags)
+            .with_shuffle_seed(field_shuffle_seed)
     }
 
     /// Look up the name of a definition across crates. This does not look at HIR.

Diff for: compiler/rustc_mir_transform/src/sroa.rs

@@ -7,7 +7,7 @@ use rustc_middle::mir::visit::*;
 use rustc_middle::mir::*;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_mir_dataflow::value_analysis::{excluded_locals, iter_fields};
-use rustc_target::abi::{FieldIdx, ReprFlags, FIRST_VARIANT};
+use rustc_target::abi::{FieldIdx, FIRST_VARIANT};
 
 pub struct ScalarReplacementOfAggregates;
 
@@ -66,7 +66,7 @@ fn escaping_locals<'tcx>(
             return true;
         }
         if let ty::Adt(def, _args) = ty.kind() {
-            if def.repr().flags.contains(ReprFlags::IS_SIMD) {
+            if def.repr().simd() {
                 // Exclude #[repr(simd)] types so that they are not de-optimized into an array
                 return true;
             }