Make block optimized ClearWithoutReferences fully shared (#24312)

diff --git a/src/System.Private.CoreLib/shared/System/SpanHelpers.cs b/src/System.Private.CoreLib/shared/System/SpanHelpers.cs
index 511b857..12b8e26 100644 (file)
--- a/src/System.Private.CoreLib/shared/System/SpanHelpers.cs
+++ b/src/System.Private.CoreLib/shared/System/SpanHelpers.cs
@@ -23,7 +23,7 @@ namespace System
             if (byteLength == 0)
                 return;
 
-#if CORECLR && (AMD64 || ARM64)
+#if !PROJECTN && (AMD64 || ARM64)
             // The exact matrix on when RhZeroMemory is faster than InitBlockUnaligned is very complex. The factors to consider include
             // type of hardware and memory aligment. This threshold was chosen as a good balance accross different configurations.
             if (byteLength > 768)