Expand CreateSpan in T0 (#91403)

Author: MichalPetryka

src/coreclr/jit/importercalls.cpp

@@ -2551,6 +2551,9 @@ GenTree* Compiler::impIntrinsic(GenTree*                newobjThis,
             // This one is just `return true/false`
             case NI_System_Runtime_CompilerServices_RuntimeHelpers_IsKnownConstant:
 
+            // Not expanding this can lead to noticeable allocations in T0
+            case NI_System_Runtime_CompilerServices_RuntimeHelpers_CreateSpan:
+
             // We need these to be able to fold "typeof(...) == typeof(...)"
             case NI_System_Type_GetTypeFromHandle:
             case NI_System_Type_op_Equality: