fixup! [naga] Support textureSampleBaseClampToEdge() for texture2d

Author: jimblandy

naga/src/back/msl/writer.rs

@@ -1950,7 +1950,11 @@ impl<W: Write> Writer<W> {
                 image,
                 sampler,
                 clamp_to_edge: true,
-                ..
+                gather: None,
+                array_index: None,
+                offset: None,
+                level: crate::SampleLevel::Zero,
+                depth_ref: None,
             } => {
                 write!(self.out, "{IMAGE_SAMPLE_BASE_CLAMP_TO_EDGE_FUNCTION}(")?;
                 self.put_expression(image, context, true)?;
@@ -1969,8 +1973,14 @@ impl<W: Write> Writer<W> {
                 offset,
                 level,
                 depth_ref,
-                clamp_to_edge: _,
+                clamp_to_edge,
             } => {
+                if clamp_to_edge {
+                    return Err(Error::GenericValidation(
+                        "ImageSample::clamp_to_edge should have been validated out".to_string(),
+                    ));
+                }
+
                 let main_op = match gather {
                     Some(_) => "gather",
                     None => "sample",