Function pointer equality comparison was not handling cross-module po…

…inters correctly when optimizations were enabled (causes target pointers to be wrapped in jump stubs sometimes). The delegate equality comparison was hitting this bug.

The DynamicGenerics test was failing in one of its delegate tests when the delegate's construction method from the shared library got inlined in the test code:
         1) One delegate was created by new'ing up a Func<> delegate (ends up creating a delegate where the delegate's thunk pointer is a jump stub to the thunk code)
         2) Another delegate was created by calling MethodInfo.CreateDelegate (ends up creating a delegate where the delegate's thunk pointer is the thunk code directly)
         3) The test was comparing the 2 delegates for equality. MulticastDelegate.Equals returned false because of the difference in the thunk pointers, even though they really point at the same target code.

[tfs-changeset: 1572883]

src/System.Private.CoreLib/src/Internal/Runtime/CompilerServices/FunctionPointerOps.cs

@@ -5,6 +5,7 @@
 using System;
 using System.Collections.Generic;
 using System.Runtime.InteropServices;
+using Internal.Runtime.Augments;
 
 namespace Internal.Runtime.CompilerServices
 {
@@ -140,7 +141,9 @@ public static unsafe bool Compare(IntPtr functionPointerA, IntPtr functionPointe
         {
             if (!IsGenericMethodPointer(functionPointerA))
             {
-                return functionPointerA == functionPointerB;
+                IntPtr codeTargetA = RuntimeAugments.GetCodeTarget(functionPointerA);
+                IntPtr codeTargetB = RuntimeAugments.GetCodeTarget(functionPointerB);
+                return codeTargetA == codeTargetB;
             }
             else
             {
@@ -153,7 +156,9 @@ public static unsafe bool Compare(IntPtr functionPointerA, IntPtr functionPointe
                 if (pointerDefA->InstantiationArgument != pointerDefB->InstantiationArgument)
                     return false;
 
-                return pointerDefA->MethodFunctionPointer == pointerDefB->MethodFunctionPointer;
+                IntPtr codeTargetA = RuntimeAugments.GetCodeTarget(pointerDefA->MethodFunctionPointer);
+                IntPtr codeTargetB = RuntimeAugments.GetCodeTarget(pointerDefB->MethodFunctionPointer);
+                return codeTargetA == codeTargetB;
             }
         }
     }

src/System.Private.CoreLib/src/System/MulticastDelegate.cs

@@ -51,7 +51,7 @@ public override sealed bool Equals(Object obj)
             {
                 if (!Object.ReferenceEquals(m_helperObject, d.m_helperObject) ||
                     (!FunctionPointerOps.Compare(m_extraFunctionPointerOrData, d.m_extraFunctionPointerOrData)) ||
-                    (m_functionPointer != d.m_functionPointer))
+                    (!FunctionPointerOps.Compare(m_functionPointer, d.m_functionPointer)))
                 {
                     return false;
                 }