8341846: [lworld] compiler/valhalla/inlinetypes/TestStressReturnBuffering.java fails to boot with genzgc

Reviewed-by: coleenp

Author: Arraying

test/hotspot/jtreg/compiler/valhalla/inlinetypes/TestStressReturnBuffering.java

@@ -27,7 +27,7 @@
  * @summary Verify that TLAB allocated buffer initialization when returning a value object works properly with oops.
  * @library /test/lib
  * @enablePreview
- * @run main/othervm -XX:CompileCommand=exclude,compiler.valhalla.inlinetypes.TestStressReturnBuffering::caller -Xmx4m
+ * @run main/othervm -XX:CompileCommand=exclude,compiler.valhalla.inlinetypes.TestStressReturnBuffering::caller -Xmx6m
  *                   compiler.valhalla.inlinetypes.TestStressReturnBuffering
  */