Revert "Silence an assert"

This reverts commit e51575b.

Author: aschwaighofer

stdlib/public/Concurrency/Task.cpp

@@ -94,10 +94,7 @@ swift::swift_task_create_f(JobFlags flags, AsyncTask *parent,
   // This means that we never get rid of this allocation.
   size_t amountToAllocate = headerSize + initialContextSize;
 
-  // TODO: if this is necessary we need to teach LLVM lowering to request async
-  // context sizes that are mulitple of that maximum alignment.
-  // For now disable this assert.
-  // assert(amountToAllocate % MaximumAlignment == 0);
+  assert(amountToAllocate % MaximumAlignment == 0);
 
   void *allocation = malloc(amountToAllocate);