Update Release Notes for 3.4.1

git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_34@208599 91177308-0d34-0410-b5e6-96231b3b80d8
Merging r201729:

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r201729 | chandlerc | 2014-02-19 17:35:01 -0500 (Wed, 19 Feb 2014) | 21 lines

Teach Clang to provide ::max_align_t in C11 and C++11 modes.

This definition is not chosen idly. There is an unfortunate reality with
max_align_t -- the specific nature of its definition leaks into the ABI
almost immediately. Because it is part of C11 and C++11 it becomes
essential for it to match with other systems on that ABI. There is an
effort to discourage any further use of this construct as a consequence
-- using max_align_t introduces an immediate ABI problem. We can never
update it to have larger alignment even as the microarchitecture changes
to necessitate higher alignment. =/

The particular definition here exactly matches the ABI of GCC's chosen
::max_align_t definition, for better or worse. This was written with the
help of Richard Smith who was decoding the exact ABI implications of the
selected definition in GCC. Notably, in-register arguments are impacted
by the particular definition chosen. =/

No one is under the illusion that this is a "good" or "useful"
definition of max_align_t, and we are working with the standards
committee to specify a more useful interface to address this need.

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git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_34@208600 91177308-0d34-0410-b5e6-96231b3b80d8
Merging r202911:

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r202911 | david.majnemer | 2014-03-04 18:43:48 -0500 (Tue, 04 Mar 2014) | 14 lines

Headers: Provide an ABI compatible max_align_t when _MSC_VER is defined

Summary:
Our usual definition of max_align_t wouldn't match up with MSVC if it
was used in a template argument.

Reviewers: chandlerc, rsmith, rnk

Reviewed By: chandlerc

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D2924

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git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_34@208601 91177308-0d34-0410-b5e6-96231b3b80d8