docs: Nuke the old release notes.

This change also removes a bunch of boilerplate and stuffing which made
it unnecessarily hard to navigate and see the comparatively miniscule
actual content that was added to this document during the 3.2
development period (or maybe even sticking around from earlier
releases...).

The new organization (a flat list) optimizes for making it easy for
people who know about changes to add them to the document.  It's
completely trivial for anyone with basic knowledge of LLVM to come in
later (such as when preparing for the actual release) and cluster any
changes into logical groups. However, I have left some comments
indicating how to add larger descriptions, if someone is feeling
adventurous ;)

Hopefully this organization will highlight how little effort is being
put into producing accurate, high-quality release notes, prompting a
corresponding improvement for the 3.3 release.

I have preserved the changes to this document that are not present
in the 3.2 release notes. There were only two... I'm pretty sure we've
been busier than that... (version control shows +213347/-173656 raw
lines just in the LLVM repo since the 3.2 release).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172954 91177308-0d34-0410-b5e6-96231b3b80d8
ReleaseNotes: note Sphinx migration.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172955 91177308-0d34-0410-b5e6-96231b3b80d8
llvm/test/Other/close-stderr.ll: Mark this as XFAIL:valgrind. We got 127 instead of 1 here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172956 91177308-0d34-0410-b5e6-96231b3b80d8
Added IRBuilder::CreateFPExtOrFPTrunc.

This method serves an analogous purpose to CreateZExtOrTrunc/CreateSExtOrTrunc
but for floating point types.

In detail, it provides a manner when one is handling conversions of floating
point types of automatically selecting fpext, fptrunc, or identity depending on
the relative bitsize of the source and destination types.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172957 91177308-0d34-0410-b5e6-96231b3b80d8