Add a few `RuntimeFeature.IsDynamicCodeSupported` conditionals. (#14284)

* Add a few `RuntimeFeature.IsDynamicCodeSupported` conditionals.

* Update RuntimeMethodInfo.cs

2 files changed, 6 insertions, 2 deletions

diff --git a/mcs/class/referencesource/mscorlib/system/activator.cs b/mcs/class/referencesource/mscorlib/system/activator.cs
index 67a42942d32..660a30f7661 100644
--- a/mcs/class/referencesource/mscorlib/system/activator.cs
+++ b/mcs/class/referencesource/mscorlib/system/activator.cs
@@ -74,7 +74,7 @@ namespace System {
                 throw new ArgumentNullException("type");
             Contract.EndContractBlock();
 #if !FULL_AOT_RUNTIME
-            if (type is System.Reflection.Emit.TypeBuilder)
+            if (RuntimeFeature.IsDynamicCodeSupported && type is System.Reflection.Emit.TypeBuilder)
                 throw new NotSupportedException(Environment.GetResourceString("NotSupported_CreateInstanceWithTypeBuilder"));
 #endif
             // If they didn't specify a lookup, then we will provide the default lookup.
diff --git a/mcs/class/referencesource/mscorlib/system/rttype.cs b/mcs/class/referencesource/mscorlib/system/rttype.cs
index 20c994fd335..8a1ce0fbd26 100644
--- a/mcs/class/referencesource/mscorlib/system/rttype.cs
+++ b/mcs/class/referencesource/mscorlib/system/rttype.cs
@@ -3782,7 +3782,7 @@ namespace System
             }
 #if !FULL_AOT_RUNTIME
             // Special case for TypeBuilder to be backward-compatible.
-            if (c is System.Reflection.Emit.TypeBuilder)
+            if (RuntimeFeature.IsDynamicCodeSupported && c is System.Reflection.Emit.TypeBuilder)
             {
                 // If c is a subclass of this class, then c can be cast to this type.
                 if (c.IsSubclassOf(this))
@@ -4303,7 +4303,11 @@ namespace System
 #if NETCORE
                     throw new NotImplementedException ();
 #else
+#pragma warning disable 162
+                    if (!RuntimeFeature.IsDynamicCodeSupported)
+                        throw new PlatformNotSupportedException();
                     return System.Reflection.Emit.TypeBuilderInstantiation.MakeGenericType(this, instantiation);
+#pragma warning restore 162
 #endif
                 }