MoonchildProductions#1251 - Part 27: Fix ifdef style.

This should do it for all the commits to files I changed, but while I'm in here I could probably go ahead and turn ALL the singular if defined statements into ifdef statements by using grep/find on the tree. On the other hand, perhaps we should do that as a separate issue so that this doesn't become a case of scope creep.

js/src/gc/Memory.cpp

@@ -685,7 +685,7 @@ MarkPagesUnused(void* p, size_t size)
         return false;
 
     MOZ_ASSERT(OffsetFromAligned(p, pageSize) == 0);
-#if defined(XP_SOLARIS)
+#ifdef XP_SOLARIS
      int result = posix_madvise(p, size, POSIX_MADV_DONTNEED);
 #else
      int result = madvise(p, size, MADV_DONTNEED);