IRGen: Remove ConformanceDescriptor::hasDependentAssociatedTypeWitnesses

This sets the 'requires instantiation' bit in a couple more cases, which
doesn't really matter because the runtime already checks a few other
conditions, such as the presence of resilient witnesses.

Author: slavapestov

lib/IRGen/ConformanceDescription.h

@@ -51,9 +51,6 @@ class ConformanceDescription {
   /// Whether this witness table requires runtime specialization.
   const unsigned requiresSpecialization : 1;
 
-  /// Whether this witness table contains dependent associated type witnesses.
-  const unsigned hasDependentAssociatedTypeWitnesses : 1;
-
   /// The instantiation function, to be run at the end of witness table
   /// instantiation.
   llvm::Constant *instantiationFn = nullptr;
@@ -66,13 +63,11 @@ class ConformanceDescription {
                          llvm::Constant *pattern,
                          uint16_t witnessTableSize,
                          uint16_t witnessTablePrivateSize,
-                         bool requiresSpecialization,
-                         bool hasDependentAssociatedTypeWitnesses)
+                         bool requiresSpecialization)
     : conformance(conformance), wtable(wtable), pattern(pattern),
       witnessTableSize(witnessTableSize),
       witnessTablePrivateSize(witnessTablePrivateSize),
-      requiresSpecialization(requiresSpecialization),
-      hasDependentAssociatedTypeWitnesses(hasDependentAssociatedTypeWitnesses)
+      requiresSpecialization(requiresSpecialization)
   {
   }
 };

lib/IRGen/GenProto.cpp

@@ -2040,7 +2040,7 @@ namespace {
       // WitnessTablePrivateSizeInWordsAndRequiresInstantiation
       B.addInt(IGM.Int16Ty,
                (Description.witnessTablePrivateSize << 1) |
-                Description.hasDependentAssociatedTypeWitnesses);
+                Description.requiresSpecialization);
       // Instantiation function
       B.addRelativeAddressOrNull(Description.instantiationFn);
       // Private data
@@ -2296,10 +2296,7 @@ void IRGenModule::emitSILWitnessTable(SILWitnessTable *wt) {
                                      wtableBuilder.getTablePrivateSize(),
                                      isDependentConformance(
                                        conf,
-                                       /*considerResilience=*/true),
-                                     isDependentConformance(
-                                       conf,
-                                       /*considerResilience=*/false));
+                                       /*considerResilience=*/true));
 
   // Build the instantiation function, we if need one.
   description.instantiationFn = wtableBuilder.buildInstantiationFunction();

test/IRGen/protocol_resilience.sil

@@ -97,8 +97,8 @@ protocol InternalProtocol {
 // -- number of witness table entries
 // CHECK-SAME:   i16 0,
 
-// -- size of private area + 'requires instantiation' bit (not set)
-// CHECK-SAME:   i16 0,
+// -- size of private area + 'requires instantiation' bit
+// CHECK-SAME:   i16 1,
 
 // -- instantiator function
 // CHECK-SAME:   i32 0
@@ -127,8 +127,8 @@ protocol InternalProtocol {
 // -- number of witness table entries
 // CHECK-SAME:   i16 0,
 
-// -- size of private area + 'requires instantiation' bit (not set)
-// CHECK-SAME:   i16 0,
+// -- size of private area + 'requires instantiation' bit
+// CHECK-SAME:   i16 1,
 
 // -- instantiator function
 // CHECK-SAME:   i32 0

test/IRGen/protocol_resilience_descriptors.swift

@@ -60,10 +60,18 @@ public struct ConditionallyConforms<Element> { }
 public struct Y { }
 
 // CHECK-USAGE-LABEL: @"$s31protocol_resilience_descriptors1YV010resilient_A022OtherResilientProtocolAAMc" =
+// -- flags: has generic witness table
 // CHECK-USAGE-SAME: i32 131072,
+// -- number of witness table entries
 // CHECK-USAGE-SAME: i16 0,
-// CHECK-USAGE-SAME: i16 0,
-// CHECK-USAGE-SAME: i32 0
+// -- size of private area + 'requires instantiation' bit
+// CHECK-USAGE-SAME: i16 1,
+// -- instantiator function
+// CHECK-USAGE-SAME: i32 0,
+// -- private data area
+// CHECK-USAGE-SAME: {{@[0-9]+}}
+// --
+// CHECK-USAGE-SAME: }
 extension Y: OtherResilientProtocol { }
 
 // CHECK-USAGE: @"$s31protocol_resilience_descriptors29ConformsWithAssocRequirementsV010resilient_A008ProtocoleF12TypeDefaultsAAMc" =