tint/sem: Remove 'sem_' prefix from array / struct tests

This is cruft left over from file name collisions between ast / sem,
which has been resolved by splitting the build targets.

Change-Id: I0d65ffe97fed7095b37cc91a506dd05a20cda76a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/106222
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>

src/tint/BUILD.gn

@@ -1163,6 +1163,7 @@ if (tint_build_unittests) {
 
   tint_unittests_source_set("tint_unittests_sem_src") {
     sources = [
+      "sem/array_test.cc",
       "sem/atomic_test.cc",
       "sem/bool_test.cc",
       "sem/builtin_test.cc",
@@ -1179,9 +1180,8 @@ if (tint_build_unittests) {
       "sem/reference_test.cc",
       "sem/sampled_texture_test.cc",
       "sem/sampler_test.cc",
-      "sem/sem_array_test.cc",
-      "sem/sem_struct_test.cc",
       "sem/storage_texture_test.cc",
+      "sem/struct_test.cc",
       "sem/texture_test.cc",
       "sem/type_manager_test.cc",
       "sem/type_test.cc",

src/tint/CMakeLists.txt

@@ -838,6 +838,7 @@ if(TINT_BUILD_TESTS)
     resolver/variable_test.cc
     resolver/variable_validation_test.cc
     scope_stack_test.cc
+    sem/array_test.cc
     sem/atomic.cc
     sem/bool_test.cc
     sem/builtin_test.cc
@@ -854,9 +855,8 @@ if(TINT_BUILD_TESTS)
     sem/reference_test.cc
     sem/sampled_texture_test.cc
     sem/sampler_test.cc
-    sem/sem_array_test.cc
-    sem/sem_struct_test.cc
     sem/storage_texture_test.cc
+    sem/struct_test.cc
     sem/texture_test.cc
     sem/type_manager_test.cc
     sem/type_test.cc