Try an experiment

Author: Catfish-Man

stdlib/public/core/ContiguousArrayBuffer.swift

@@ -274,15 +274,15 @@ internal struct _ContiguousArrayBuffer<Element>: _ArrayBufferProtocol {
          realMinimumCapacity._builtinWordValue, Element.self)
 
       let storageAddr = UnsafeMutableRawPointer(Builtin.bridgeToRawPointer(_storage))
-      if let allocSize = _mallocSize(ofAllocation: storageAddr) {
-        let endAddr = storageAddr + allocSize
-        let realCapacity = endAddr.assumingMemoryBound(to: Element.self) - firstElementAddress
-        _initStorageHeader(
-          count: uninitializedCount, capacity: realCapacity)
-      } else {
+//      if let allocSize = _mallocSize(ofAllocation: storageAddr) {
+//        let endAddr = storageAddr + allocSize
+//        let realCapacity = endAddr.assumingMemoryBound(to: Element.self) - firstElementAddress
+//        _initStorageHeader(
+//          count: uninitializedCount, capacity: realCapacity)
+//      } else {
         _initStorageHeader(
           count: uninitializedCount, capacity: realMinimumCapacity)
-      }
+//      }
     }
   }
 

stdlib/public/core/StringStorage.swift

@@ -206,17 +206,17 @@ fileprivate func _allocate<T: AnyObject>(
   let totalTailBytes = total - numHeaderBytes
 
   let object = tailAllocator(totalTailBytes)
-  if let allocSize = _mallocSize(ofAllocation:
-    UnsafeRawPointer(Builtin.bridgeToRawPointer(object))) {
-    _internalInvariant(allocSize % MemoryLayout<Int>.stride == 0)
-
-    let realNumTailBytes = allocSize - numHeaderBytes
-    _internalInvariant(realNumTailBytes >= numTailBytes)
-
-    return (object, realNumTailBytes)
-  } else {
+//  if let allocSize = _mallocSize(ofAllocation:
+//    UnsafeRawPointer(Builtin.bridgeToRawPointer(object))) {
+//    _internalInvariant(allocSize % MemoryLayout<Int>.stride == 0)
+//
+//    let realNumTailBytes = allocSize - numHeaderBytes
+//    _internalInvariant(realNumTailBytes >= numTailBytes)
+//
+//    return (object, realNumTailBytes)
+//  } else {
     return (object, totalTailBytes)
-  }
+//  }
 }
 
 fileprivate func _allocateStringStorage(