Fix crossgen2 R2R issues found by static analysis

src/coreclr/tools/Common/Compiler/EventPseudoDesc.cs

@@ -93,7 +93,16 @@ public EventPseudoDesc(EcmaType type, EventDefinitionHandle handle)
 
         public override string ToString() => $"{_type}.{Name}";
 
-        public static bool operator ==(EventPseudoDesc a, EventPseudoDesc b) => a._type == b._type && a._handle == b._handle;
+        public static bool operator ==(EventPseudoDesc a, EventPseudoDesc b)
+        {
+            if (a is null)
+                return b is null;
+
+            if (b is null)
+                return false;
+
+            return a._type == b._type && a._handle == b._handle;
+        }
 
         public static bool operator !=(EventPseudoDesc a, EventPseudoDesc b) => !(a == b);
     }

src/coreclr/tools/Common/Compiler/PropertyPseudoDesc.cs

@@ -88,7 +88,16 @@ public PropertyPseudoDesc(EcmaType type, PropertyDefinitionHandle handle)
 
         public override string ToString() => $"{_type}.{Name}";
 
-        public static bool operator ==(PropertyPseudoDesc a, PropertyPseudoDesc b) => a._type == b._type && a._handle == b._handle;
+        public static bool operator ==(PropertyPseudoDesc a, PropertyPseudoDesc b)
+        {
+            if (a is null)
+                return b is null;
+
+            if (b is null)
+                return false;
+
+            return a._type == b._type && a._handle == b._handle;
+        }
 
         public static bool operator !=(PropertyPseudoDesc a, PropertyPseudoDesc b) => !(a == b);
     }

src/coreclr/tools/aot/ILCompiler.ReadyToRun/Compiler/DependencyAnalysis/ReadyToRunCodegenNodeFactory.cs

@@ -208,7 +208,7 @@ public ModuleAndIntValueKey(int integer, EcmaModule module)
                 Module = module;
             }
 
-            public bool Equals(ModuleAndIntValueKey other) => IntValue == other.IntValue && ((Module == null && other.Module == null) || Module.Equals(other.Module));
+            public bool Equals(ModuleAndIntValueKey other) => IntValue == other.IntValue && Module == other.Module;
             public override bool Equals(object obj) => obj is ModuleAndIntValueKey && Equals((ModuleAndIntValueKey)obj);
             public override int GetHashCode()
             {

src/coreclr/tools/aot/ILCompiler.ReadyToRun/Compiler/DependencyAnalysis/ReadyToRunSymbolNodeFactory.cs

@@ -633,20 +633,6 @@ public Import GenericLookupHelper(
                         (MethodWithToken)helperArgument,
                         methodContext);
 
-                case ReadyToRunHelperId.MethodDictionary:
-                    return GenericLookupMethodHelper(
-                        runtimeLookupKind,
-                        ReadyToRunFixupKind.MethodHandle,
-                        (MethodWithToken)helperArgument,
-                        methodContext);
-
-                case ReadyToRunHelperId.TypeDictionary:
-                    return GenericLookupTypeHelper(
-                        runtimeLookupKind,
-                        ReadyToRunFixupKind.TypeDictionary,
-                        (TypeDesc)helperArgument,
-                        methodContext);
-
                 case ReadyToRunHelperId.VirtualDispatchCell:
                     return GenericLookupMethodHelper(
                         runtimeLookupKind,

src/coreclr/tools/aot/ILCompiler.ReadyToRun/Compiler/ReadyToRunCodegenCompilation.cs

@@ -655,13 +655,14 @@ public bool IsInheritanceChainLayoutFixedInCurrentVersionBubble(TypeDesc type)
                 if (CompilationModuleGroup.TypeLayoutCompilationUnits(type).HasMultipleInexactCompilationUnits)
                     return false;
 
-                while (!type.IsObject && type != null)
+                while (!type.IsObject)
                 {
                     if (!IsLayoutFixedInCurrentVersionBubble(type))
                     {
                         return false;
                     }
                     type = type.BaseType;
+                    Debug.Assert(type != null);
                 }
             }
 

src/coreclr/tools/aot/ILCompiler.ReadyToRun/TypeSystem/Mutable/MutableModule.Sorting.cs

@@ -1,22 +1,17 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System;
-using System.Threading;
-
 using Debug = System.Diagnostics.Debug;
 
 namespace Internal.TypeSystem.Ecma
 {
     partial class MutableModule
     {
-        // This isn't deterministic, but it is functional. At this time, since only 1 MutableModule is contained in a build, it will be deterministic as it will always return 0.
-        static int s_globalIndex = 0;
-
-        int _index = Interlocked.Increment(ref s_globalIndex);
+        // There is only ever a single MutableModule in a build, so any comparison is against itself.
         public int CompareTo(MutableModule other)
         {
-            return _index.CompareTo(_index);
+            Debug.Assert(this == other);
+            return 0;
         }
     }
 }