[ir] Reject arrayed multisampled textures

This are not valid in WGSL and not currently used in any Tint flow.

Change-Id: I671bf71fea27e952308e08d042d82c35c24d25f0
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/256574
Reviewed-by: dan sinclair <dsinclair@chromium.org>
Commit-Queue: James Price <jrprice@google.com>

src/tint/lang/core/ir/validator.cc

diff --git a/src/tint/lang/core/ir/validator.cc b/src/tint/lang/core/ir/validator.cc
index 325e71d..10f89f3 100644
--- a/src/tint/lang/core/ir/validator.cc
+++ b/src/tint/lang/core/ir/validator.cc
@@ -2024,7 +2024,6 @@
 
                 switch (ms->Dim()) {
                     case core::type::TextureDimension::k2d:
-                    case core::type::TextureDimension::k2dArray:
                         break;
                     default:
                         diag() << "invalid multisampled texture dimension: "

src/tint/lang/core/ir/validator_type_test.cc

diff --git a/src/tint/lang/core/ir/validator_type_test.cc b/src/tint/lang/core/ir/validator_type_test.cc
index 97eb509..fe4b4bd 100644
--- a/src/tint/lang/core/ir/validator_type_test.cc
+++ b/src/tint/lang/core/ir/validator_type_test.cc
@@ -512,7 +512,7 @@
                                      std::make_tuple(false, TypeBuilder<core::type::Void>)),
                      testing::Values(std::make_tuple(false, core::type::TextureDimension::k1d),
                                      std::make_tuple(true, core::type::TextureDimension::k2d),
-                                     std::make_tuple(true, core::type::TextureDimension::k2dArray),
+                                     std::make_tuple(false, core::type::TextureDimension::k2dArray),
                                      std::make_tuple(false, core::type::TextureDimension::k3d),
                                      std::make_tuple(false, core::type::TextureDimension::kCube),
                                      std::make_tuple(false,