IRGen: Stop using FieldAccess::NonConstantIndirect

I'm not ripping it out completely, because I'm going to repurpose
it for something else.

Author: slavapestov

lib/IRGen/GenClass.cpp

@@ -170,12 +170,6 @@ namespace {
     //   - or has a field with resilient layout.
     bool ClassMetadataRequiresDynamicInitialization = false;
 
-    // Does the superclass have a fixed number of stored properties?
-    // If not, and the class has generally-dependent layout, we have to
-    // access stored properties through an indirect offset into the field
-    // offset vector.
-    bool ClassHasFixedFieldCount = true;
-
     // Does the class have a fixed size up until the current point?
     // If not, we have to access stored properties either ivar offset globals,
     // or through the field offset vector, based on whether the layout has
@@ -304,9 +298,7 @@ namespace {
           //
           // FIXME: We need to implement indirect field/vtable entry access
           // before we can enable this
-          if (IGM.Context.LangOpts.EnableClassResilience) {
-            ClassHasFixedFieldCount = false;
-          } else {
+          if (!IGM.Context.LangOpts.EnableClassResilience) {
             addFieldsForClass(superclass, superclassType);
             NumInherited = Elements.size();
           }
@@ -405,16 +397,7 @@ namespace {
 
       // If layout depends on generic parameters, we have to load the
       // offset from the class metadata.
-
-      // If the layout of the class metadata is statically known, then
-      // there should be a fixed offset to the right offset.
-      if (ClassHasFixedFieldCount) {
-        return FieldAccess::ConstantIndirect;
-      }
-
-      // Otherwise, the offset of the offset is stored in a global variable
-      // that will be set up by the runtime.
-      return FieldAccess::NonConstantIndirect;
+      return FieldAccess::ConstantIndirect;
     }
   };
 } // end anonymous namespace

test/IRGen/class_resilience.swift

@@ -14,7 +14,6 @@
 // CHECK: @_T016class_resilience33ClassWithResilientlySizedPropertyC5colors5Int32VvpWvd = {{(protected )?}}global [[INT]] 0
 
 // CHECK: @_T016class_resilience14ResilientChildC5fields5Int32VvpWvd = {{(protected )?}}global [[INT]] {{8|16}}
-// CHECK: @_T016class_resilience21ResilientGenericChildC5fields5Int32VvpWvi = {{(protected )?}}global [[INT]] {{56|88}}
 
 // CHECK: @_T016class_resilience26ClassWithResilientPropertyCMo = {{(protected )?}}constant [[INT]] {{52|80}}
 
@@ -231,10 +230,8 @@ public class MyResilientChild : MyResilientParent {
 
 // CHECK-NEXT: [[ADDR:%.*]] = getelementptr inbounds %T16class_resilience21ResilientGenericChildC, %T16class_resilience21ResilientGenericChildC* %0, i32 0, i32 0, i32 0
 // CHECK-NEXT: [[ISA:%.*]] = load %swift.type*, %swift.type** [[ADDR]]
-// CHECK-NEXT: [[INDIRECT_OFFSET:%.*]] = load [[INT]], [[INT]]* @_T016class_resilience21ResilientGenericChildC5fields5Int32VvpWvi
-// CHECK-NEXT: [[ISA_ADDR:%.*]] = bitcast %swift.type* [[ISA]] to i8*
-// CHECK-NEXT: [[FIELD_OFFSET_TMP:%.*]] = getelementptr inbounds i8, i8* [[ISA_ADDR]], [[INT]] [[INDIRECT_OFFSET]]
-// CHECK-NEXT: [[FIELD_OFFSET_ADDR:%.*]] = bitcast i8* [[FIELD_OFFSET_TMP]] to [[INT]]*
+// CHECK-NEXT: [[ISA_ADDR:%.*]] = bitcast %swift.type* [[ISA]] to [[INT]]*
+// CHECK-NEXT: [[FIELD_OFFSET_ADDR:%.*]] = getelementptr inbounds [[INT]], [[INT]]* [[ISA_ADDR]], [[INT]] 11
 // CHECK-NEXT: [[FIELD_OFFSET:%.*]] = load [[INT]], [[INT]]* [[FIELD_OFFSET_ADDR:%.*]]
 // CHECK-NEXT: [[OBJECT:%.*]] = bitcast %T16class_resilience21ResilientGenericChildC* %0 to i8*
 // CHECK-NEXT: [[ADDR:%.*]] = getelementptr inbounds i8, i8* [[OBJECT]], [[INT]] [[FIELD_OFFSET]]