Merge pull request #640 from jozefkucia/fix-stencil-reference-value

Mark stencil reference value as dirty in MVKCmdClearAttachment command.
diff --git a/MoltenVK/MoltenVK/Commands/MVKCmdTransfer.mm b/MoltenVK/MoltenVK/Commands/MVKCmdTransfer.mm
index 8991223..48547c3 100644
--- a/MoltenVK/MoltenVK/Commands/MVKCmdTransfer.mm
+++ b/MoltenVK/MoltenVK/Commands/MVKCmdTransfer.mm
@@ -962,6 +962,8 @@
     cmdEncoder->setVertexBytes(mtlRendEnc, _vertices.data(), vtxCnt * sizeof(_vertices[0]), vtxBuffIdx);
     [mtlRendEnc drawPrimitives: MTLPrimitiveTypeTriangle vertexStart: 0 vertexCount: vtxCnt];
     [mtlRendEnc popDebugGroup];
+
+	cmdEncoder->_stencilReferenceValueState.markDirty();
 }