[sre] Register a canonical reflected method for a methodspec token. (Fixes #60233) (#5813)

* [test] ILGenerator test for duplicate methodspec tokens

Regression test for [Bugzilla #60233](https://bugzilla.xamarin.com/show_bug.cgi?id=60233)

* [sre] mono_dynamic_image_register_token: Change asserts to warnings

This partly relaxes the changes in 792b5367cd3a6ffa1a192c4d2d7ace3509cbb646
which added the assertions.

In practice the assertions introduced a crash in heavy uses of
System.Reflection.Emit such as unit testing frameworks and dynamic languages.
We still want to know if there are surprising uses of
mono_dynamic_image_register_token, but we don't need a crash.  SRE used to work
before 792b5367cd3a6ffa1a192c4d2d7ace3509cbb646, so no need to break it.

* [sre] Register a canonical reflected method for a methodspec token (Fixes #60233)

This is like the fix for [bugzilla
59364](https://bugzilla.xamarin.com/show_bug.cgi?id=59364) but this time it's a
methodspec token, not a memberref token.

1 files changed, 42 insertions, 3 deletions

diff --git a/mcs/class/corlib/Test/System.Reflection.Emit/ILGeneratorTest.cs b/mcs/class/corlib/Test/System.Reflection.Emit/ILGeneratorTest.cs
index c943d6859ca..b31ed2e117e 100644
--- a/mcs/class/corlib/Test/System.Reflection.Emit/ILGeneratorTest.cs
+++ b/mcs/class/corlib/Test/System.Reflection.Emit/ILGeneratorTest.cs
@@ -524,11 +524,13 @@ namespace MonoTests.System.Reflection.Emit
 			
 		}
 
-		public class Base {
+		public class Base<T> {
 			public int x;
+
+			public void M () { }
 		}
 
-		public class Derived : Base {
+		public class Derived : Base<string> {
 		}
 
 		[Test]
@@ -540,7 +542,7 @@ namespace MonoTests.System.Reflection.Emit
 			//
 			// Regression test for bugzilla #59364
 
-			var f1 = typeof (Base).GetField ("x");
+			var f1 = typeof (Base<string>).GetField ("x");
 			var f2 = typeof (Derived).GetField ("x");
 
 			var value_getter = typeof (RuntimeFieldHandle).GetProperty("Value").GetMethod;
@@ -572,5 +574,42 @@ namespace MonoTests.System.Reflection.Emit
 			Assert.AreEqual ("1", s);
 		}
 
+		[Test]
+		public void MethodSpecTokenSame () {
+			DefineBasicMethod ();
+			// Get the same method from a base generic instance and
+			// a type derived from it so that the
+			// MemberInfo:DeclaredType differs but the tokens are
+			// the same.
+			//
+			// Regression test for bugzilla #60233
+
+			var m1 = typeof (Base<string>).GetMethod ("M");
+			var m2 = typeof (Derived).GetMethod ("M");
+
+			var il = il_gen;
+
+			var loc = il.DeclareLocal (typeof (Derived));
+
+			il.Emit (OpCodes.Newobj, typeof (Derived).GetConstructor(new Type[]{}));
+			il.Emit (OpCodes.Stloc, loc);
+			il.Emit (OpCodes.Ldloc, loc);
+			il.Emit (OpCodes.Call, m1);
+			il.Emit (OpCodes.Ldloc, loc);
+			il.Emit (OpCodes.Call, m2);
+			il.Emit (OpCodes.Ldstr, "1");
+			il.Emit (OpCodes.Ret);
+
+			var baked = tb.CreateType ();
+
+			var x = Activator.CreateInstance (baked);
+			var m = baked.GetMethod ("F");
+
+			var s = m.Invoke (x, null);
+
+			Assert.AreEqual ("1", s);
+
+		}
+
 	}
 }