Revert "cppgc: Add temporary CHECK for diagnosing issue"

This reverts commit d1538091.

Reason for revert: https://ci.chromium.org/ui/p/chromium/builders/try/android-marshmallow-arm64-rel/1022301/overview

Original change's description:
> cppgc: Add temporary CHECK for diagnosing issue
>
> Bug: chromium:1253650
> Change-Id: I634501d5f092263ebd0f96826c79655c49ddce3b
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3302792
> Reviewed-by: Anton Bikineev <bikineev@chromium.org>
> Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#78096}

Bug: chromium:1253650
Change-Id: I2e8ff73e8bac5379a86985f19558dbfa5caae94f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3302796
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Owners-Override: Nico Hartmann <nicohartmann@chromium.org>
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78100}

include/cppgc/persistent.h

@@ -189,9 +189,6 @@ class BasicPersistent final : public PersistentBase,
   // heterogeneous assignments between different Member and Persistent handles
   // based on their actual types.
   V8_CLANG_NO_SANITIZE("cfi-unrelated-cast") T* Get() const {
-#ifdef V8_TARGET_OS_ANDROID
-    IsValid();
-#endif  // V8_TARGET_OS_ANDROID
     // The const_cast below removes the constness from PersistentBase storage.
     // The following static_cast re-adds any constness if specified through the
     // user-visible template parameter T.
@@ -234,12 +231,7 @@ class BasicPersistent final : public PersistentBase,
     // Ideally, handling kSentinelPointer would be done by the embedder. On the
     // other hand, having Persistent aware of it is beneficial since no node
     // gets wasted.
-    const auto* value = GetValue();
-    const bool is_valid = value != nullptr && value != kSentinelPointer;
-#ifdef V8_TARGET_OS_ANDROID
-    CPPGC_CHECK(!is_valid || GetNode());
-#endif  // V8_TARGET_OS_ANDROID
-    return is_valid;
+    return GetValue() != nullptr && GetValue() != kSentinelPointer;
   }
 
   void Assign(T* ptr) {