Introduce a V8_NORETURN macro and use it to make GCC 4.9.2 happy again.

src/heap/spaces-inl.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_SPACES_INL_H_
 #define V8_HEAP_SPACES_INL_H_
 
 #include "src/heap/spaces.h"
 #include "src/heap-profiler.h"
 #include "src/isolate.h"
@@ skipping 428 matching lines @@
   }
 
   MSAN_ALLOCATED_UNINITIALIZED_MEMORY(obj->address(), size_in_bytes);
 
   return obj;
 }
 
 
 AllocationResult NewSpace::AllocateRawUnaligned(int size_in_bytes) {
   Address top = allocation_info_.top();
-  if (allocation_info_.limit() - top < size_in_bytes) {
+  if (allocation_info_.limit() < top + size_in_bytes) {
     // See if we can create room.
     if (!EnsureAllocation(size_in_bytes, kWordAligned)) {
       return AllocationResult::Retry();
     }
 
     top = allocation_info_.top();
   }
 
   HeapObject* obj = HeapObject::FromAddress(top);
   allocation_info_.set_top(top + size_in_bytes);
@@ skipping 24 matching lines @@
 
 
 intptr_t LargeObjectSpace::Available() {
   return ObjectSizeFor(heap()->isolate()->memory_allocator()->Available());
 }
 
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_SPACES_INL_H_