[clang] [clang-tools-extra] [lldb] [llvm] [Allocator] Drop RedZoneSize (non-sanitizer) and BytesAllocated members (PR #205711)

[Fangrui Song via cfe-commits]

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@@ -335,14 +331,11 @@ class BumpPtrAllocatorImpl
   /// Custom-sized slabs allocated for too-large allocation requests.
   SmallVector<std::pair<void *, size_t>, 0> CustomSizedSlabs;
 
-  /// How many bytes we've allocated.
-  ///
-  /// Used so that we can compute how much space was wasted.
-  size_t BytesAllocated = 0;
-
+#if LLVM_ADDRESS_SANITIZER_BUILD
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MaskRay wrote:

Good catch. Gated member presence on LLVM_ENABLE_ABI_BREAKING_CHECKS and the variable use on both conditions.

https://github.com/llvm/llvm-project/pull/205711