[wasm] Move test-backing-store.cc to wasm directory

This is a wasm-only test, hence move it to the wasm directory and skip
it in no-wasm builds.

R=ahaas@chromium.org

Bug: v8:11238
Change-Id: I57c9abbb98c3415f4d759372d479e1f61464217f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2731536Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73152}

test/cctest/BUILD.gn

@@ -201,7 +201,6 @@ v8_source_set("cctest_sources") {
     "test-api.h",
     "test-array-list.cc",
     "test-atomicops.cc",
-    "test-backing-store.cc",
     "test-bignum-dtoa.cc",
     "test-bignum.cc",
     "test-bit-vector.cc",
@@ -414,6 +413,7 @@ v8_source_set("cctest_sources") {
       "../common/wasm/flag-utils.h",
       "../common/wasm/test-signatures.h",
       "../common/wasm/wasm-macro-gen.h",
+      "wasm/test-backing-store.cc",
       "wasm/test-c-wasm-entry.cc",
       "wasm/test-compilation-cache.cc",
       "wasm/test-gc.cc",

test/cctest/test-backing-store.cc → test/cctest/wasm/test-backing-store.cc

@@ -5,12 +5,12 @@
 #include "src/api/api-inl.h"
 #include "src/objects/backing-store.h"
 #include "src/wasm/wasm-objects.h"
-
 #include "test/cctest/cctest.h"
 #include "test/cctest/manually-externalized-buffer.h"
 
 namespace v8 {
 namespace internal {
+namespace wasm {
 
 using testing::ManuallyExternalizedBuffer;
 
@@ -22,7 +22,7 @@ TEST(Run_WasmModule_Buffer_Externalized_Detach) {
     HandleScope scope(isolate);
     MaybeHandle<JSArrayBuffer> result =
         isolate->factory()->NewJSArrayBufferAndBackingStore(
-            wasm::kWasmPageSize, InitializedFlag::kZeroInitialized);
+            kWasmPageSize, InitializedFlag::kZeroInitialized);
     Handle<JSArrayBuffer> buffer = result.ToHandleChecked();
 
     // Embedder requests contents.
@@ -81,5 +81,6 @@ TEST(BackingStore_Reclaim) {
 }
 #endif
 
+}  // namespace wasm
 }  // namespace internal
 }  // namespace v8