Fix multisample texture operations crashing HLSL generation

This includes a partial implementation of multisample texture
operations on the HLSL backend. It can't be fully tested yet, since
the API side isn't implemented.

BUG=angleproject:1442
TEST=dEQP-GLES31.functional.shaders.builtin_functions.texture_size.*
     (successfully compiles instead of crashing)

Change-Id: Ief782db28388a3f8fd8113cc86ce3c4f500f322a
Reviewed-on: https://chromium-review.googlesource.com/443264
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>
diff --git a/src/compiler/translator/UtilsHLSL.h b/src/compiler/translator/UtilsHLSL.h
index e5ece0a..61fd1ef 100644
--- a/src/compiler/translator/UtilsHLSL.h
+++ b/src/compiler/translator/UtilsHLSL.h
@@ -31,12 +31,15 @@
     HLSL_TEXTURE_CUBE,
     HLSL_TEXTURE_2D_ARRAY,
     HLSL_TEXTURE_3D,
+    HLSL_TEXTURE_2D_MS,
     HLSL_TEXTURE_2D_INT4,
     HLSL_TEXTURE_3D_INT4,
     HLSL_TEXTURE_2D_ARRAY_INT4,
+    HLSL_TEXTURE_2D_MS_INT4,
     HLSL_TEXTURE_2D_UINT4,
     HLSL_TEXTURE_3D_UINT4,
     HLSL_TEXTURE_2D_ARRAY_UINT4,
+    HLSL_TEXTURE_2D_MS_UINT4,
 
     // Comparison samplers