llvm-svn: 189001

PageSize, aka AllocationGranularity, is 65536 on Win32 (and Cygwin).

llvm-svn: 188999

Run in two different modes: with and without reopening the temporary file
between creating it and mapping it with MemoryBuffer.

llvm-svn: 186986

The main observation is that we never need both the filesize and the map size.
When mapping a slice of a file, it doesn't make sense to request a null
terminator and that would be the only case where the filesize would be used.

There are other cleanups that should be done in this area:

* A client should not have to pass the size (even an explicit -1) to say if
  it wants a null terminator or not, so we should probably swap the argument
  order.
* The default should be to not require a null terminator. Very few clients
  require this, but many end up asking for it just because it is the default.

llvm-svn: 186984

llvm-svn: 186887

llvm-svn: 169250

Patch by Daniel Malea.

llvm-svn: 165246